Cmd/Cvar: move /toggle and /cycle to BaseCommand
Cvar: Remove Cvar_CheckRange that wasn't implemented
Cvar: remove Cvar_SetIFFlag and Cvar_ValidateString

Cvar_IfFlag was just there to bypass the string check for one var
The only problems of having "\;... in a var name is for the autogen we
can quote the set commands in the autogen instead.
Remove more unused cvar code

The latched calls made sense but where useless because their were almost
never used. It will work as is with the rewrite anyway.