Error message returns JSON parse error in alert to user

[alexdryden]

When uploading a media item with a file extension that isn't allowed, a JSON parse error message is displayed instead of the the custom error text:

This is because the error message is not passed with the self keyword here:

scalar/system/application/libraries/File_Upload.php

Line 61 in a9165f1

throw new Exception(FILE_NAME_NOT_ALLOWED);

It should be throw new Exception(self::FILE_NAME_NOT_ALLOWED);. I can submit a pr for this along with the other error message related issue.

[craigdietrich]

A pull request here, too, would be excellent, thanks @alexdryden !