Remove the quad primitive type

It's not supported by OpenGL ES 2.0
Make quads available for rendering with

While we won't use them internally, custom shapes from users may
be drawn with quads.
Corrected a mispelled library name in FindGLES.cmake
Source files renamed (lowercase)

- renamed directories and main headers
- renamed modules source files
- renamed examples source files
- updated CMake scripts to find new paths
Slash trailing up to 80
SFML detects the Android platform
Implemented a workaround to the missing pthread_cancel for Android
Reimplemented the native activity glue code provided by the NDK

It removes useless stuff and uses the SFML system module.
Renamed getStates() to retrieveStates()
Forgot to delete the allocated states
Share states across the SFML modules and it saves the created window

1) The activity states are shared across the SFML modules with the function getActivityStates()
2) It saves the window when created or destroyed so the window module can use it
OpenGL ES headers are properly included on Android
The Android WindowHandle is defined (void*)
Moved sfml_set_option macro into the macro file (Macro.cmake)
Added Android toolchain and platform cmake files
CMake recognizes the Android platform and invokes the right build commands
CMake now builds the system module
Disabled joystick stuff when compiling for Android
Implemented WindowImplAndroid
Fixed mutexes and locks (misunderstanding)