Adding an "residues_to_include" option to the CartesianSampler mover
eg. residues_to_include="1-1612" lets CartesianSampler know these are
residues to refine.
Unlike the option "residues=" which can only be used under "user"mode,
"residues_to_include" can designate any residues in all the
residue-selection modes (eg. auto, density, rama). This option
can be useful for users to specify additional residues while using
automatic error predictors to select residues to refine.