DVB signal strength indicator: Replace F abbreviation by S.

F was used for "Force" which is French for "Strength"
Translation scripts: Faster backup step.

Skip verify after copy, the speed penalty is really big and this backup isn't critical.

Also fix the backup of the main RC after 051a39a5deb63c1507cf0a2d305e8fc2eeb26ee3.
build.bat: Compilation failed if MSYS or MinGW paths contained a space.
Output page: Remove an old always overriden tooltip.