Adopt a more consistent naming convention for latexml-specific contro…

[brucemiller]

…l-sequences.

They usually should start with \lx@, to avoid conflicts with external styles, classes, formats, etc.

To assist in updating any user bindings, a warning is issued when the old names are used (but the new name will be executed).
For reference (and tool building) The old and new names are listed here:

\@ERROR \lx@ERROR
\@@eqno \lx@eqno
\LTX@nonumber \lx@equation@nonumber
\normnal@par \lx@normal@par
\inner@par \lx@normal@par
\hidden@bgroup \lx@hidden@bgroup
\hidden@egroup \lx@hidden@egroup
\right@hidden@egroup \lx@hidden@egroup@right
\hidden@align \lx@hidden@align
\hidden@noalign \lx@hidden@noalign
\hidden@cr \lx@hidden@cr
\hidden@crcr \lx@hidden@crcr
\@start@alignment \lx@start@alignment
\@finish@alignment \lx@finish@alignment
\@close@alignment \lx@close@alignment
\if@in@alignment \if@in@lx@alignment
\@alignment@hline \lx@alignment@hline
\@alignment@newline \lx@alignment@newline
\@alignment@newline@noskip \lx@alignment@newline@noskip \@alignment@newline@marker \lx@alignment@newline@marker \@alignment@newline@markertall \lx@alignment@newline@markertall \@alignment@column \lx@alignment@column
\@alignment@ncolumns \lx@alignment@ncolumns
\@alignment@bindings \lx@alignment@bindings
\@row@before \lx@alignment@row@before
\@row@after \lx@alignment@row@after
\@column@before \lx@alignment@column@before
\@column@after \lx@alignment@column@after
\@tabular@begin@heading \lx@alignment@begin@heading \@tabular@end@heading \lx@alignment@end@heading
\@multicolumn \lx@alignment@multicolumn
\@dollar@in@normalmode \lx@dollar@in@normalmode
\@dollar@in@mathmode \lx@dollar@in@mathmode
\@dollar@in@textmode \lx@dollar@in@textmode
\math@underline \lx@math@underline
\text@underline \lx@text@underline
\math@overleftarrow \lx@math@overleftarrow
\math@overrightarrow \lx@math@overrightarrow
\@@BEGININLINEMATH \lx@begin@inline@math
\@@ENDINLINEMATH \lx@end@inline@math
\@@BEGINDISPLAYMATH \lx@begin@display@math
\@@ENDDISPLAYMATH \lx@end@display@math
\@@BEGININLINETEXT \lx@begin@inmath@text
\@@ENDINLINETEXT \lx@end@inmath@text
\@@FLOATINGSUBSCRIPT \lx@floating@subscript
\@@FLOATINGSUPERSCRIPT \lx@floating@superscript
\@@POSTSUBSCRIPT \lx@post@subscript
\@@POSTSUPERSCRIPT \lx@post@superscript
\@ASSERT@MEANING \lx@assert@meaning

DG: Updating with code block to avoid @-tagging github users

[dginev]

Walked through the code changes - all looks good.

It is a little scary, but the newly achieved consistency is a very neat improvement.