Merge pull request #1643 from RosettaCommons/roccomoretti/fix_option_space_parsing
Fix option space parsing regression
A feature used relatively frequently by the Meiler Lab in ligand docking is the ability to concatenate PDBs by quoting. e.g. -s "protein.pdb ligand.pdb" instead of manually concatenating the two PDBs into a single-file complex.
A recent change to the option system broke this functionality. (It would also break other situations where you'd have a space in a file name.) Surprisingly, the functionality appears not to have been tested.
This commit restores the previous behavior, as well as adding tests to confirm the functionality is preserved.