Fixes XNAT-1382: Clean up empty image assessor directories after deletion.
Fixes XNAT-2673: Added warning if Overwrite flag is not checked on the Manage Files Upload File Form.
XNAT-2892, XNAT-2893: Fixed checks for permissions to run searches, so that explicitly allowing user to run secured searches would override implicitly forbidden operations.

xdat changes include the changeset https://bitbucket.org/nrg/xdat_1_6dev/commits/05c39f9bc5f8334f447d9e97147567a37f773c16
XNAT-2873 Made it so subject tab always shows up on project page.
XNAT-2892: Fixed code where check for isActive caused meta-data error on stored searches.

Changes to xdat-1.6.3 jars corresponds to changeset https://bitbucket.org/nrg/xdat_1_6dev/commits/25025459dfbe17c1f388e11219a639fed4a82b68.
XNAT-2876: Set default for CSRF emails to false.

Jar changes correspond to https://bitbucket.org/nrg/xdat_1_6dev/commits/9784b1a3d15093e436154bfe7244b7278984ee8b