Fixing issue with deferred image process for single occurring image fiel...

Fixing issue with deferred image process for single occurring image fields. Now all images are processed with jQuery Deferred() and when.done they options.success is fired. Still need to handle multiple images per field, but this gets us close and fixes the issue where multiple image fields on a form create multiple nodes; renamed local function _image_field_form_validate to _image_fields_form_validate to better describe its function.