Removed hook_field_attach_delete and added submit handler to image remove_button to delete original image

Conflicts:
	imagefield_crop.js
	imagefield_crop.module

A few variables names got lost when moving between 6 and 7 syntax, which
cause the box ratio to stop working. Crop area seemed to be used for
cropping and resolution - I have separated these out now.

Also, I have re-introduced the 'Enforce minimum crop size based on the
output size' setting which is needed for all combinations of settings to
work correctly.

preview shows existing file until user starts marking new crop. This overcomes the limitation in D7 that we cannot save the metadata with the file

when cropping, saving the original aside, and recrop the original onto the same file every time. New nodes crash miserably though