Bundle LLVM Clang with CodeBlocks distribution

[gh_origin]

Alongside with MinGW? I think it will make the distribution bloated. Instead we could put a link on the Download page to tell the user if they need LLVM Clang they could get it there, too. You could use my distribution of LLVM Clang here: http://forums.next.codeblocks.org/index.php/topic,24267.0.html