Undeprecate commandline params forcequotacheck, fastboot, and forcefsck

Undeprecate commandline params forcequotacheck, fastboot, and forcefsck

Those are historical names, but there is nothing wrong with them. The files on
/ (/fastboot, /forcefsck, and /forcequotacheck) are problematic because they
require a modification of the root file system. But the commandline params work
fine. They have the obvious advantage compared to our "modern" option that they
are much easier to type without looking up the spelling in the docs. Undeprecate
them to avoid unnecessary churn.