[#783] Update strings for approved/rejected entries

Moderated entries are deleted from the modlog table once deleted, so
this was causing errors in the inbox. Update the messages everywhere to
just say "this entry has been handled".
Merge pull request #783 from afuna/approved-moderated-entry-inbox-bug-783

inbox message is warning when notifying of moderated community post
[#788] Automatically give posting access to invited users

* ... but only if postlevel == "members" (any member, everyone including
  non-members)

* if postlevel == "select", then we go by whether the checkbox is
  selected
Merge pull request #788 from afuna/poster-on-invite-bug-788

Members not getting posting access in communities when they accept invite
Merge branch 'release-1.20' into develop

* release-1.20:
  [#788] Automatically give posting access to invited users
  [#783] Update strings for approved/rejected entries