Added SDL_ttf library

Added SDL_ttf library
    android/initialize_project.sh
    src/Android.mk
    src/SConscript
    src/graphics/SDL_ttf.h   (+)
Added core/MainManager, updated main.cpp

Added core/MainManager, updated main.cpp
    src/core/MainManager.cpp (+)
    src/core/MainManager.h   (+)
    src/main.cpp