~azzar1/unity/add-show-desktop-key

Changed semantics of "published" property: Now applies to directories, not
files, and causes everything in the directory to get published.

fileservice: Listing only shows "published" for directories.
studpath.authorized_public: Checks parent directory for publish permission
    instead of the file itself.

(This comes out of a series of meetings with Tom and Steven, where we decided
that file-level access is too fine grained; you can't control user-generated
files).