Figure out why there is a nullpointerexception  -_-
TODO: Create an event queue and process it in every time step
Nice work! Finally get the player movement working and the way this game
handles the input is very flexible! Another good news: Patrick finally
got the audio system working xD
Things to do during weekends, (if i have time, really - -) start
designing weapon system and shooting and damaging and throwing grenade
and planting timer bombs blah blah blah.. Long way to go!
Figure out a way to draw the flying path of each bullet
TODO: Work on the rendering
Implemented MachineGunWeapon ,switchWeapon() and bullets' flying path.
TODO: throw Grenade
Added MouseWheelMove() support in RuleModel, set up customized zoom-in
and zoom-out, made camera following player(but it's still buggy)
Working on stairs. Getting into one-way wall and going to do something
dangerous. So this commit is to back things up = =
Merge remote-tracking branch 'origin/RuleModel-Branch' into
Patrick-Branch

Conflicts:
	Blockadia/bin/components/BuildConfig.class
	Blockadia/bin/rules/BeatIt/BeatItCustomGame$Difficulty.class
	Blockadia/bin/rules/BeatIt/BeatItCustomGame.class
	Blockadia/bin/rules/BeatIt/BeatItGame$Difficulty.class
	Blockadia/bin/rules/BeatIt/BeatItGame.class
	Blockadia/src/components/BuildConfig.java
	Blockadia/src/rules/BeatIt/BeatItCustomGame.java
	Blockadia/src/rules/BeatIt/BeatItGame.java