Switched to trapezoidal screws at the corners of each piston

The 'precision' threaded rods weren't very precise, so I'm switching to TR10x2 leadscrews.

Removed the smooth rods in favor of leadscrews to help keep the pistons aligned properly, and to save cost. This adds extra pulleys, but they're cheaper than the smooth rods.
Added slots to the piston walls for the pistons
Moved the x-motor off of the x-carriage

Lots of details to be handled still. The motor placement isn't ideal and the frame may need to be enlarged.
Reworked the Y-axis idler pulley

Switched to a custom acrylic mounting plate. The old one from inventables was fully threaded, which caused the pulley to talk up and down. It also wasn't long enough.
More x-axis rework

Added a bracket for the x-axis idler and moved the motor
Added belt anchors to the x-carriage
Enlarged the frame to accommodate the new motor placement
Added turned-ends to the leadscrews
Removed all MXL pulleys

Long live GT2
Added flanged bearings for the leadscrews
Reduced the number of mounting bolts needed for BottomRetainer

Using 4 bolts was overkill for such a small part
Fixed the top deck orientation mark
Removed BackPanel

It should have been deleted after importing from sintertest, but it was missed.
Refactored the handling of the leadscrew length

Now everything is based off of ZRailAssembly.height rather than Z_RAIL_LENGTH. ZRailAssembly.height is determined by BUILD_VOLUME.z.

This should help with changing the build volume.
Ignore Bundler state
Added a Guardfile

'bundle exec guard' will launch guard and watch for changes to any of the ruby files. On change, it rebuilds the SketchUp file.
Inverted the Z-axis motors

Moving them to the bottom side of the deck panel considerably shortens the overall height of the structure
Fixed ChamberSidePanel slot generation

The slots in the ChamberFrontPanel and not auto-generated from the tabs on ChamberSidePanel
Swapped the pillow blocks for leadscrew nut blocks

This was somehow missed in the "Great Conversion to Trapezoidal Screws of 2014".