Re #14: WIP. Added table for selecting which transforms to calculate metrics for.
Re #14: WIP. Removed hidden transforms from transform selection table.
Re #14: WIP. Python metrics are calculated for selected transforms.
Re #14: Update transform selection table when changed.
Re #14: Modified layout to use QToolbox type display.
Merge pull request #19 from mholden8/master

Fixes #14: Compute metrics for any transform in the scene.