Administrative description of a preset

Patches correctly on 6.x-2.0-beta10 and with fuzz on current dev. Could be committed as-is, but probably should have further discussion.

Updated patch which puts the description on the same row, removes the empty description default text, and uses the description in the formatter labels.

It also changes the formatters to be based on the presetid, so it will break all the formatters when applied. This would solve the problem or changing the imagecache preset path breaking formatters in the future.

corrected whitespace
this should solve #594592: Human readable preset names

Marking as ImageCache 3.x Todo.

#594592: Human readable preset names