Improved mouse events on OS X regarding fullscreen mode
Add keypad return, equal and period keys support for OS X

Related to #401
Now using inotify on Linux to avoid constantly polling joystick connections (#96)

Conflicts:
	src/sfml/window/Linux/JoystickImpl.cpp
	src/sfml/window/Linux/JoystickImpl.hpp
	src/sfml/window/Win32/JoystickImpl.cpp
	src/sfml/window/Win32/JoystickImpl.hpp