+ BaseUnit.cpp, BaseUnit.h: new _selected flag.
+ Camera.cpp, Camera.h: linear movement has been taken over quadratic movement. Also, cursor now moves if dealing with screen borders.
+ Cursor.cpp, Cursor.h: new Cursor class holds cursor X/Y information. It is meant to be contained inside a HumanPlayer object.
* Game.cpp: minor changes in casts and comments.
+ HumanPlayer.cpp: added callbacks for button release events.
* HumanPlayer.cpp, HumanPlayerBtn.cpp: button handling has been transferred from HumanPlayer.cpp to HumanPlayerBtn.cpp in order to improve modularity.
+ Sprite.cpp: sprite data was not being checked against NULL.
- Unit.cpp: drawHandler() is now executed by Player object.
XaviDCR92