New opcode handlers, two fixes and new icons

Pulling my two last commits ^^:

- New icons for both servers

- Added the following opcode handlers:
MoveTurnWithMouse, MovePitchWithMouse, MoveJump, MoveFallStop, MoveFallLand, MoveStartFlyingUp, MoveStartFlyingDown, MoveStopFlying, MoveStartStrafeLeft, MoveStartStrafeRight, MoveStopStrafe, MoveCollisionAtJump, ForceWalkSpeedChangeAck, ForceFlightSpeedChangeAck, ForceSwimSpeedChangeAck, ForceRunSpeedChangeAck, MoveSetCanFlyAck
Coded and tested one by one

- Fixed MoveStartBackward opcode:
Using the right order to write mask and flags bits after vector data.

- Fixed ObjectUpdateFailed opcode (seen at Mogale's fork):
Using the right guidMask bit order

Hope it helps :)