New -f command line option for find-like behavior

[IonoclastBrigham]

It would be nice if, instead of having to store intermediate search results, or process images in a shell loop, we could tell ivy "do the search, and then apply any other commands to each item in the search results instead of displaying them, as if each in-turn were the image path argument.

Because this is similar to in behavior to the UNIX tool find (1), this issue proposes the mnemonic option -f.

Examples

# find all images tagged "maui" and also tag them "beach"
ivy -fe -a maui -A beach

# locate pictures of animals and move them to a new directory
ivy -f -o dog,cat,naked-mole-rat -M /home/foo/pikshuhs/aminals/

Further thought should be given as to the exact command line syntax. Does order matter? Are there any other special cases that take multiple input files?

[IonoclastBrigham]

Thinking about this some more, do we even need the -f switch? If you get one more more query options instead of a path, could just iterate any modification commands over the result list.