Added selected token hightlighting - similar to hightlighting occurences...

... of selected text, but 'smarter'.

New highlighter will check if declaration of found word is same as declaration of token pointed by cursor.

Hi Alpha!
p2rkw here. I added semantic highlight to your plugin. Code may be bit dirty because I only had few hours, sorry. 

Btw. what's the purpose of ClangProxy? I guess you tries to use libclang only inside ClangProxy, buy it makes things much harder and more complicated. If my code violated your class design feel free to fix my code :)
Greetings, p2rkw.