Use proper plural forms for some UI strings
Add wxPLURAL to the patterns extracted by make_pot.sh
Update string extraction for desktop file
Update version in make_pot.sh to 3.2
Update aegisub.pot
Eliminate a bunch of pointless copies of the selection set
Add rref overloads to SetSelectedSet and SetSelectionAndActive
Slather on some std::moves when setting the selection
Replace rref + const ref overloads with one version taking by value
Make everything final that can be

Apparently gcc does use final for devirtualization.