Advanced selection logic

It's currently difficult to select multiple, discontiguous regions of a protein. SHIFT+Click is useful for selecting a range; CTRL+Click is useful for adding a single residue to a selection; but they cannot be used well in conjunction.

E.g. To select select residues [2-10; 20-25], I would like to: Click 2, SHIFT+Click 10, CTRL+Click 20, SHIFT+Click 25