Z Wobble Fix (Solidoodle 3 & 4)

UPDATE: New source file 'zwobblefix_final' allows movement along the x and y axis.

A quick fix we can up with for out own Solidoodle 3 & 4. We're still testing but we believe it fixed z wobble problems by 50-60%. Next step is to add a firmware fix to see if with can solve the issue up to 85-100%.

Please print, test and let us know how it goes.