Create a new shared pointer type stdext::shared_object_ptr and stdext::shared_obj
using boost::intrusive_ptr
Advantages:
* half memory usage
* faster and lightweight
Disadvantages:
* using weak_ptr is not supported anymore
* compiling seems slower
* A lot of changes in lua binder to compile with clang's libc++
* Add more portability to luabinder
* Remove const keyword from bound lua functions
* Deprecate std::bind usage with luabinder replace its usage with registerSingletonClass/bindSingletonFunction for binding singleton classes
* Fix a bug in lua binder where calling functions with bil object would make the client crash
* More fixes to compile with clang
* Add cotire cmake module to speedup compilation https://github.com/sakra/cotire
* Fix clang error and warnings
* Rename Font to BitmapFont to fix conflict with Xlib.g Font typedef
* Remove legacy PCH support
* Improve Position hash