Include more file extensions for C++ lexer.
Include more file extensions for C++ lexer.

Fixes #809

zmughal/pygments-mirror,zmughal/pygments-mirror,zmughal/pygments-mirror,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,zmughal/pygments-mirror,sol/pygments,sol/pygments,zmughal/pygments-mirror,zmughal/pygments-mirror,zmughal/pygments-mirror,sol/pygments,sol/pygments,sol/pygments,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,sol/pygments,zmughal/pygments-mirror,sol/pygments,sol/pygments,zmughal/pygments-mirror