Use preprocessor highlighting from cc-mode

[gracjan]

Emacs cc-mode has font-lock definitions for preprocessor. Those include support for #include highlighting with strings, nice coloring for #define, line continuations and other perks. All of this is lacking in current Haskell mode preprocessor highlighing.

haskell-mode should use:

• (require 'cc-mode)
• (c-initialize-cc-mode)
• (font-lock-add-keywords nil c-font-lock-keywords-1)
• check if other changes are needed
• check that the above changes only font-lock for preprocessor and nothing else

cc-mode is bundled with Emacs these days so it can be relied upon.

[gracjan]

Caveat: it seems that # is to be recognized only on first column, although I did not find it documented anywhere.

[gracjan]

Note though #1131. This one seems to be in conflict, so closing.