Refactoring on function_types.hpp performed to slim down some of the calls: could use more refactoring
Drastically simplified userdata's binding capabilities: constructor supports both `:` and `.` syntax (but member functions DO NOT).
All tests are passing
It's going to take serious work to make it happen in GCC, plus the fact that 4.9 is still giving me
so many errors I can't even read it...
I'll let Rapptz figure it out, but later.
Sexy class bindings, yes!