[FEATURE REQUEST] Sort messages by read/unread status

[DarthPleurotus]

Most SMS apps don't allow you to sort message threads by whether or not you have read the latest message. This feature alone would put QKSMS head and shoulders above the competition in my opinion.

This is particularly useful given that QKSMS already allows you to re-mark messages as unread. If I need to quickly read over a message and don't have time to respond, I can mark it as unread with confidence that I won't lose track of it.