Marblevator remix

Small modifications and addons to the execelent design by gzumwalt and Linax.

I kept having problems that the edges of the track would rip off during printing, so I added a small block of support to the tracks, 1cm long, as wide as the track.
This is only 0.2mm thick, so should only be on 1-2layers and can be cut off after printing.

Modified the arm to be 0.2mm less wide, since on my printer at least the original one is a bit too thick, since the top already keeps it fixed somewhat, the arm does not need to fit tightly in the tessel.

Added:
20cm long straight track to the collection, for longer runs.
180 degree turn for full turns, may add one with room for support in the middle if needed.
Tessel and base in one based on bjorntm´s design, extended it with 25 and 50mm

TODO:
split/combine?
Base and Tessel in one : http://www.thingiverse.com/thing:697680