redhen_membership 7.x-1.0-beta2

Changes since 7.x-1.0-beta1:

• Use entity metadata wrappers for getting related entities
• Change update op to edit to match other RedHen modules.
• #1744944: Change membership uri to include associated entity uri: Change membership entity uri to include associated entity uri
• #1715988: Limit Views relationships for memberships: Limit Views relationships for memberships. Use custom views controller.
• Use ops from entity_access for membership permissions.
• #1711110: support for modifying start/end dates via VBO: support for VBO. Added setter callback for membership_state