Add tooltips and controller-learning entries for new key detection controls.

Refer to the old "rate" control as "Speed Control" from now on instead of "Pitch
Control" to avoid confusion.
Fix EngineBufferScaleLinearTest. I forgot to update the test when I changed the meaning of pitch_adjust in EngineBufferScale::setScaleParameters.
Fix typos in Key Detection preferences pane
Update translation templates. Found 1330 source text(s) (97 new and 1233 already existing). Kept 12 obsolete entries
MSVC really does need an intermediate int cast
Cosmetic change in “Relocate to directory” dialog