Enable to lock direction (used when hit)
Fixed set_lock_direction() in Body class and restored MekaDragons a bit.
Fixed bug with accelration less than 10 for Player and Monster.
Added possibility to lock scrolling for world.
1. Corrected starting location when entering Mekas from from castle.
2. Fixed bug for Body::get_fall()
3. Added water_treshold attribute to player.
Merge pull request #11 from baijkal/master

Fixed to Body class, lock scrolling and water_treshold attribute