Merge pull request #5929 from RosettaCommons/roccomoretti/interactive_ligand_tweak
[Foldit] Add Ligand Tweak action
This PR adds a "Ligand Tweak" action for designable ligands, which, when selected from the action bar, pops up purple tweak arrows on the rotatable bonds of the ligand, and allows you to rotate them back and forth. The concept is that it would be used with the torsion objective to optimize placement/torsions of the ligand.
The tool should not be available for residues/puzzles which aren't designable ligands.