c: add more type keywords
c: introduce expr_bol for non-label line starts
fix tokens from nested `#if 0`

and cover #ifdef and #ifndef in the nesting
use `super` in C++ keyword defs
cpp: put pseudo keywords in :statements
Implement RegexLexer::State#inspect
better error behavior for non-existing states
c++: spec inner classes
c: add a stub for builtins
add an objective c lexer

closes #27