og 7.x-2.4

Changes since 7.x-2.3:

DRUPAL-SA-CONTRIB-2013-095 - Organic Groups - Access bypass

• Better validate group audience fields.
• Fix migrate related failing test.
• #2118253 by NofarG: Incorrect docs in og_ui_subscribe()
• #1997280 by NofarG: incorrect docs for og_get_all_group_entity()?
• #1981406 by RoySegall: Field cache isn't cleared after saving an OG membership
• #2099193 by czigor: Variable name typo
• #1565546 follow up: Move migrate files under correct folder.
• #2087789 by joachim: UI, DX, and performance improvements to _og_access_verify_access_field_existence()
• #1565546 by SebCorbin, pgillis: OG User Roles (OGUR) upgrade path
• #1816800 by othermachines, hernani: Integration of OG Grant Roles with Rules
• #2063385 by ezra-g: _og_access_verify_access_field_existence() assumes node group type, throws an exception rebuilding node access
• #1983450 by Cottser: Can't unset og_node_create_links destination
• #2058709 by Kars-T: og_node_access() should use countReferencableEntities() instead of getReferencableEntities