Fixed player x-z movement while falling/jumping.

While jumping/falling, you will move half the normal speed in the x-z
plane. This allows you to easily jump on blocks.
Old situation: Movement in the x-z plane was not possible while
jumping/falling.
*sigh* Merge remote-tracking branch 'origin/master'

Conflicts:
	Unity project/Assets/New Terrain.asset
	Unity project/Assets/Scenes/Level.unity