ec_file 6.x-1.0-rc4

MUCH happier with the stability of this module.

* Added a field to views called 'Product: Sell' which says if a file is marked to be sold or not.
* When deleting a node which is selling a file, remove those files from the ec_file database.
* Added an additional confirmation question when requesting to delete a single node when that node
has file products attached to it, and those files have been purchased by a customer.
* Broke out the logic for putting ec_file data into the $node object into its
own function - ec_file_node_load()
* New function - ec_file_delete()
* New function - ec_file_presave() - adds or removes a file product to the database
* Adding and removing sellable files now works properly.