Fix support for the "delete conversations" admincp option when "litigation hold" feature is used. This works-around an XF2 bug where conversations can be left in an inconsistent state.
Fix some cases where conversation label sort order is not respected in the admincp
Improve robustness of upgrade code for very old XF1 versions (~v1.2.x)
Fix upgrading from XF1.x using XF2.1+
Respect prefix value when using inline mod copy-to-thread option
Setup to allow Multi Prefix to correctly extend copy-to-thread feature
Requires MultiPrefix v2.5.1 for full multi-prefix support
Fix 'prefix' checkbox layout bug with XF2.1
Cleanup some phrases references to XF1 'filtered' tab rather than the XF2 'conversation labels/rules'
Fix rule handling for conversations which have a deleted conversation starter
Do not send an inbox_full alert when replying that a user can not start a conversation
Rework maximum messages error message phrasing
Check maximum messages limit before creating or inviting with another user into a conversation
UI.X compatibility fix w.r.t to participant list
Handle race condition when creating conversation metadata
Fix disabling "Conversations Searchable" did not removing UI elements indicating conversation search is possible