Added a dependency to file module.

Issue #1574702 by micheas : In upload_nodes_upload_form_submit, use of _upload_nodes_file_uri_to_object instead of file_uri_to_object (belonging to plupload formerly, and media actually).
In _upload_nodes_get_manageable_targets, added a initialisation of $targets in order to avoid a notice in case of no target defined.

Removed specific preview of image, standard one is used now.
Code clean up.

Titles are all the same (#1300286) bugfix.

Added the possibility to display fields on the upload form to be able to set the same value for all uploaded node.
Added the possibility to remove fields from the edit form so it is possible to hide a field that have been filled on$
For that, the edit phase process has been changed and a configuration page has been added.