ultimaker original mod: printhead/extrusion head cover

fits the rev.3 extrusion head of the ultimaker original!
you dont need to modify anything.
the little recess on the right side will give enough space for the heat-couple-cables (red/yellow).
the second little part will follow soon, if you dont like the grid on the top - make some suggestions! ;)
this is a remix! thank you for the .ipt files jwag55!
_changelog:_
20140614 1500 (v2):
changed the height and the grid, also the design of the recess