Fix footnotes. (#188)

* Fix footnotes.

1. Skip over brackets inside footnotes. Otherwise things like PCites
   and other bracketed comments wrongly match and end the footnote
   early.

2. Allow for inline formatting inside footnotes.

3. Allow for footnotes to appear in lists.

Author: bwhelm

syntax/pandoc.vim

@@ -405,7 +405,7 @@ call s:WithConceal('abbrev', 'syn match pandocAbbreviationTail /\]/ contained co
 "
 syn match pandocFootnoteID /\[\^[^\]]\+\]/ nextgroup=pandocFootnoteDef
 "   Inline footnotes
-syn region pandocFootnoteDef start=/\^\[/ end=/\]/ contains=pandocReferenceLabel,pandocReferenceURL,pandocLatex,pandocPCite,,pandocEnDash,pandocEmDash,pandocEllipses,pandocBeginQuote,pandocEndQuote,@Spell skipnl keepend 
+syn region pandocFootnoteDef start=/\^\[/ skip=/\[.\{-}]/ end=/\]/ contains=pandocReferenceLabel,pandocReferenceURL,pandocLatex,pandocPCite,pandocCiteKey,pandocStrong,pandocEmphasis,pandocStrongEmphasis,pandocNoFormatted,pandocSuperscript,pandocSubscript,pandocStrikeout,pandocEnDash,pandocEmDash,pandocEllipses,pandocBeginQuote,pandocEndQuote,@Spell skipnl keepend 
 call s:WithConceal("footnote", 'syn match pandocFootnoteDefHead /\^\[/ contained containedin=pandocFootnoteDef', 'conceal cchar='.s:cchars["footnote"])
 call s:WithConceal("footnote", 'syn match pandocFootnoteDefTail /\]/ contained containedin=pandocFootnoteDef', 'conceal')
 
@@ -419,24 +419,24 @@ call s:WithConceal("footnote", 'syn match pandocFootnoteIDTail /\]/ contained co
 " List Items: {{{2
 "
 " Unordered lists
-syn match pandocUListItem /^>\=\s*[*+-]\s\+-\@!.*$/ nextgroup=pandocUListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocReferenceURL,pandocAutomaticLink skipempty display
+syn match pandocUListItem /^>\=\s*[*+-]\s\+-\@!.*$/ nextgroup=pandocUListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocReferenceURL,pandocAutomaticLink,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID skipempty display
 call s:WithConceal('list', 'syn match pandocUListItemBullet /^>\=\s*\zs[*+-]/ contained containedin=pandocUListItem', 'conceal cchar='.s:cchars['li'])
 
 " Ordered lists
-syn match pandocListItem /^\s*(\?\(\d\+\|\l\|\#\|@\)[.)].*$/ nextgroup=pandocListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink skipempty display 
+syn match pandocListItem /^\s*(\?\(\d\+\|\l\|\#\|@\)[.)].*$/ nextgroup=pandocListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID skipempty display 
 " support for roman numerals up to 'c'
 if g:pandoc#syntax#roman_lists != 0
     syn match pandocListItem /^\s*(\?x\=l\=\(i\{,3}[vx]\=\)\{,3}c\{,3}[.)].*$/ nextgroup=pandocListItem,pandocMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation,pandocAutomaticLink skipempty display 
 endif
 syn match pandocListItemBullet /^(\?.\{-}[.)]/ contained containedin=pandocListItem
 syn match pandocListItemBulletId /\(\d\+\|\l\|\#\|@.\{-}\|x\=l\=\(i\{,3}[vx]\=\)\{,3}c\{,3}\)/ contained containedin=pandocListItemBullet
 
-syn match pandocListItemContinuation /^\s\+\([-+*]\s\+\|(\?.\+[).]\)\@<!\([[:alpha:]ñäëïöüáéíóúàèìòùłßÄËÏÖÜÁÉÍÓÚÀÈÌÒÙŁß_"[]\|\*\S\)\@=.*$/ nextgroup=pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation,pandocListItem contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocReferenceURL,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink contained skipempty display 
+syn match pandocListItemContinuation /^\s\+\([-+*]\s\+\|(\?.\+[).]\)\@<!\([[:alpha:]ñäëïöüáéíóúàèìòùłßÄËÏÖÜÁÉÍÓÚÀÈÌÒÙŁß_"[]\|\*\S\)\@=.*$/ nextgroup=pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocDelimitedCodeBlock,pandocListItemContinuation,pandocListItem contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocReferenceURL,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID contained skipempty display 
 " }}}
 " Definitions: {{{2
 "
-syn region pandocDefinitionBlock start=/^\%(\_^\s*\([`~]\)\1\{2,}\)\@!.*\n\(^\s*\n\)\=\s\{0,2}[:~]\(\~\{2,}\~*\)\@!/ skip=/\n\n\zs\s/ end=/\n\n/ contains=pandocDefinitionBlockMark,pandocDefinitionBlockTerm,pandocCodeBlockInsideIndent,pandocEmphasis,pandocStrong,pandocStrongEmphasis,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocFootnoteID,pandocReferenceURL,pandocReferenceLabel,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink,pandocEmDash,pandocEnDash
-syn match pandocDefinitionBlockTerm /^.*\n\(^\s*\n\)\=\(\s*[:~]\)\@=/ contained contains=pandocNoFormatted,pandocEmphasis,pandocStrong,pandocLaTeXInlineMath nextgroup=pandocDefinitionBlockMark
+syn region pandocDefinitionBlock start=/^\%(\_^\s*\([`~]\)\1\{2,}\)\@!.*\n\(^\s*\n\)\=\s\{0,2}[:~]\(\~\{2,}\~*\)\@!/ skip=/\n\n\zs\s/ end=/\n\n/ contains=pandocDefinitionBlockMark,pandocDefinitionBlockTerm,pandocCodeBlockInsideIndent,pandocEmphasis,pandocStrong,pandocStrongEmphasis,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocFootnoteID,pandocReferenceURL,pandocReferenceLabel,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocAutomaticLink,pandocEmDash,pandocEnDash,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID
+syn match pandocDefinitionBlockTerm /^.*\n\(^\s*\n\)\=\(\s*[:~]\)\@=/ contained contains=pandocNoFormatted,pandocEmphasis,pandocStrong,pandocLaTeXInlineMath,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID nextgroup=pandocDefinitionBlockMark
 call s:WithConceal("definition", 'syn match pandocDefinitionBlockMark /^\s*[:~]/ contained', 'conceal cchar='.s:cchars["definition"])
 " }}}
 " Special: {{{2