LUN-967: Filter PermissionAdmin for folder onwer.
LUN-967: Add tests for folder permission admin acl.
LUN-967: Fix function signatures for failing tests.
Revert "LUN-967: Fix function signatures for failing tests."

This reverts commit eb25eceff4277f38ecdf92184a2050bd3741bdd6.
Add Retina support to filer when using easy thumbnails
Changed function signature get_thumbnail_name to be compatible with easy_thumbnails supporting hires images
LUN-967: Add admin view tests.
LUN-967: Tidy up admin view tests.
LUN-967: Tiny up remaining permission admin tests.
Merge pull request #15 from pbs/LUN-967

Lun 967