SECURITY: Users now need the manage_options capability to view or modify the roles assigned to a membership level. Users who can edit levels without that capability now see a read-only list of the level's assigned roles. #54 (@dparker1005)
SECURITY: Submitted role mappings are now validated against the roles offered in the level settings UI so that a tampered request cannot assign hidden roles such as administrator or another level's role. #54 (@dparker1005)
BUG FIX: Deleting a membership level now removes that level's role from any users who still have it. #54 (@dparker1005)