Merged SDL2 changes from bartbes/love-experiments/SDL2 into default.

- Added love.system module, including clipboard functions.

- Added custom hardware cursors (love.mouse.newCursor, love.mouse.setCursor.)

- Revamped love.joystick:
-- added Joystick objects and moved love.joystick functions which operated on individual joysticks to methods on the Joystick objects.
-- Added love.joystick.getJoystick and love.joystick.getJoystickCount.
-- Added events for when joysticks are connected and disconnected.
-- Added 'Gamepad' methods to Joystick objects: Joystick:isGamepad, Joystick:getGamepadAxis, and Joystick:isGamepadDown. They're a common abstraction for xbox controller-like joystick across operating systems.

- Added monitor choosing support and "fullscreen desktop" mode to love.window.

- Moved unicode text input events to their own callback function (love.textinput), removed the key repeat functions from love.keyboard and made the second argument of love.keypressed a boolean saying whether the keypress was a repeat.

- liblove now works with love.window and love.graphics in OS X

src/modules/mouse/sdl/Mouse.h

@@ -23,6 +23,7 @@
 
 // LOVE
 #include "mouse/Mouse.h"
+#include "Cursor.h"
 
 namespace love
 {
@@ -38,6 +39,17 @@ public:
 	// Implements Module.
 	const char *getName() const;
 
+	Mouse();
+	~Mouse();
+
+	love::mouse::Cursor *newCursor(love::image::ImageData *data, int hotx, int hoty);
+	love::mouse::Cursor *newCursor(love::mouse::Cursor::SystemCursor cursortype);
+
+	void setCursor(love::mouse::Cursor *cursor);
+	void setCursor();
+
+	love::mouse::Cursor *getCursor() const;
+
 	int getX() const;
 	int getY() const;
 	void getPosition(int &x, int &y) const;
@@ -49,6 +61,11 @@ public:
 	bool isVisible() const;
 	void setGrab(bool grab);
 	bool isGrabbed() const;
+
+private:
+
+	love::mouse::Cursor *curCursor;
+
 }; // Mouse
 
 } // sdl