imagefield_crop 6.x-1.0-beta3

This beta release is coordinated with imagefield & filefield new API change, so be sure to upgrade these modules to filefield-6.x-3.0-beta2 and imagefield-6.x-3.0-beta2.

As always when upgrading, make your backups.

List of changes from previous beta:
* #397912 by quicksketch: adapt to new filefield hook structure, as imagefield is just a widget and not a field anymore
* #212576 by yhager: flush imagecache presets after crop
* use imageapi instead of direct gd calls