Added thumb, wrist, and updated palm structures.

Added more distant elastic tie offs to the palm, and uploaded the thumb
and wrist pieces.

Note: All files currently have tolerances which work well for my
printer. Tolerances can be adjusted for people, and inventor files
provided by request.
Revert "Added thumb, wrist, and updated palm structures."

This reverts commit 2d8086f84f6b2081a6bb1e44b908b2eca28f01a0.
Adde thumb, wrist, and updated palm structures.

Added elastic tie offs back by the wrist to palm structures, so that the
% change in length of the elastic is reduced. This produces a more
constant retracting force.

Also uploaded wrist and thumb parts. Note: Thumb can be replaced easily
with alternative angles.