Inconsistent Motion values

Relates to:

• MC-80649
• MC-80880

Mobs

It seems like all Mobs have this Motion when not moving:

Motion:[0:0.0d,1:-0.0784000015258789d,2:0.0d]

This might cause problems when testing for an entity based on its Motion value (this won't work currently anyways because of MC-80649).

Minecarts

Another strange this is, that for example Minecarts placed on a rail has this motion:

Motion:[0:0.0d,1:-0.0d,2:0.0d]

But it seems like the game makes no difference between 0.0 and -0.0, so this wouldn't be problematic I guess