Customizable Spring Footings for Replicator 2/2X Build Plate

After upgrading the [extruder](http://www.thingiverse.com/thing:59129), adding a [hood and side panels](http://www.thingiverse.com/thing:46069), adding a glass build plate, adding [aluminium arms](http://www.thingiverse.com/thing:84729), and firming up the build plate [pads](http://www.thingiverse.com/thing:43050), my Replicator 2 was still prone to occasional registration errors (misaligned edges) during filament changes mid print. I tracked down the problem to the lack of spring footings. This