ARGO-226 & ARGO-227:  change instances of 'None' to 'Citation Only' for displaying object rights selection in UI.  start overhauling RegistrationController#rights_list since logic as-is is clearly somewhat broken (e.g. the various conditions set up the rights list should be mutually exclusive, but aren't).  will need confirmation from others on exact correct behavior.  start updating related unit tests for correctness and readability.
Merge branch 'develop' into obj_rights_ARGO-226_ARGO-227
ARGO-226, ARGO-227: fix options values in default_rights_options
ARGO-226: fix specified default for options_for_select for default_rights_options
ARGO-226: fix specified default for options_for_select for default_rights_options
ARGO-227: fix rights_list logic after getting clarification on what the rightsMetadata xml can look like.  fix unit tests for the 'Citation Only', 'Dark', and no default specified cases
ARGO-227: refactor rights_list to make it less verbose and to clean up comments
ARGO-227: have rights_list check group tag for 'stanford', leave todo comment about making that more robust.  add a test case with a non-stanford group.  improve test case descriptions, remove a commented out pending.app/controllers/registration_controller.rb
ARGO-227: have rights_list check group tag for 'stanford', leave todo comment about making that more robust.  add a test case with a non-stanford group.  improve test case descriptions, remove a commented out pending.
Merge branch 'develop' into obj_rights_ARGO-226_ARGO-227
ARGO-227: fix rights_list to preserve options ordering