Tab completion should prefer most recently used, not alphabetical sort

Tab completion is wonderful, allowing me to tab complete using any substring in the name.  If the channel contains members "anexample", "example", and "someoneelse", then `@ex` will show tab-completion entries for "anexample" and "example".

This is good.

What isn't good is that the completion ordering is *always* alphabetical, and typing TAB will complete the *first* entry in the completion list.

Which means when I *always* chat with "example", and *never* with "anexample", then typing `@ex [TAB]` will always result in "@anexample".

Could tab completion please use a "most recently completed" list, such that if I've "not recently" mentioned @anexample but I *have* recently mentioned @example, then `@ex [TAB]` completes to who I've most recently mentioned: @example.

(If easier to implement, this need not be a per-user "most recently used" list. The most recent speaker in the channel history would also be an improvement, especially if @anexample has never ever written a message in the channel, yet still shows up in the member list, because the member list is per-server and not per-channel.)