Remove two deprecated headers from <cocos2d.h>.

- 2d/CCLabelTTF.h and CCLabelBMFont.h .
[Android] Add brittle-build directory and Android make project.
Fix: GNU C++ doesn't support static_assert in .c file ...

- Add a int cast in XXH_STATIC_ASSERT() to prevent Visual C++ warning.
[Android] The Android.mk projects now is ready to run Brittle apps.