Model - Get rid of the 4 walk animations and only leave one, which looks good...

Model - Get rid of the 4 walk animations and only leave one, which looks good for all directions. Also add a Walk + Mine animation, since Irrlicht doesn't support blending the two animations otherwise

Update player script to match the animations in the previous commit

Shorten the still mine animation so the hand matches the speed of the walk-mine animation

Reduce animation speed to half when sneaking