Updating uploads controller

* Converts uploads controller to use $model->find() in place of
  datasource, eliminating a bug related to the $ds logic.
* Adds HTML5 multiple file upload capability.
Improving userauth_local helper

* Fixes a bug in email/username branching logic causing username
  authentication to fail in some instances.
* Adds 'cleartext' encryption type (only intended for migration from
  old data).