remove highlight of other languages from reST

emove the reST HL rules to include syntax highlighting of specific languages for code blocks.

I'm rather on the fence about actually merging this, as it can be seen as a regression. OTOH it avoids silly things like including C++/Python/Doxygen styles in CMake (e.g. see http://commits.kde.org/kate/9695f1785ad8 ).

kill the duplicated rest hl file

REVIEW: 116580