`scrot -f` shouldn't "work"

[guijan]

Scrot's -f option modifies -s's behavior. However, if you specify just -f by itself, scrot goes on as usual. I'm a fan of strict option parsing, this should error. There are many other cases like this in the program, like -b or -c.

[N-R-K]

It's possible that someone has aliased scrot to something like: scrot -b -c -f or similar. This way if he does scrot -s the bcf flags act as "defaults". Otherwise if no -s was specified, it goes on as usual.

If we start erroring out then it'll be much more difficult to accomplish that.