Fixed game over condition checking via logic and slightly lowered the plane to be below the trigger. Added obstacles in world 2. Added a simple transition between world. Added all bgm asset. Added playing bgm in title screen.

- Added R key to restart game immediately.
- Added GameInfo as a shared static variables across classes.
- Fixed collider for trigger to cover all area of plane (ground).
- Commented out code to print out debug-log about spawning new objects.
Added more sfx and music asset. Added AudioPlayer class to play sfx. Fixed winning/losing state by lowering down the plane more.
Merge branch 'master' of github.com:haxpor/LD27

Conflicts:
	unityproj/Assets/scenes/scene_game_world1.unity