Fix throwing error when variable not found
Highlight possible duplicate accounts with the same user or domain name
Show people waiting in the mod queue
Add "current thread OP post id" parameter for merge reply messages
Fix thread titles when merging through the normal merge process
Unmerge from the merge log thread instead of the mod log thread
Fix report process foreground colour in all themes
Updated version number to 3.21

Actual command: ./release.sh 3.21