Fixed temp download file permissions. Fixed learning object importer link. Fixed dspace upload mimetype nil exception

Ensuring the databse connections are cleared once workers are done. Redirecting download to uploaded files while DSpace upload is not finished.

Removing requisition of "complaint" from parameters in the rejection or acceptance of the complaints.

Overwriting SessionsController from devise_token_auth gem to treat blocking and banishing mechanisms in the user session.

Implemented user show_submission action; Fixed submission update callback; Added Trackable to Submission and CuratorAssignment

Modifying complaint_reason table, setting a new column "status" to define its state (active or inactive), as well as giving it a controller to allow users that has "editor" or  "administrator" as role to create and update its entries

Complaints can now be geted individually identified by the id code (show) and only editors and administrators can see the complaints.