SELinux: Fix resolution of extra entries

Signed-off-by: Sol Jerome <sol.jerome@gmail.com>
schemas: Add abstract SELinux entries

Signed-off-by: Sol Jerome <sol.jerome@gmail.com>
wrote unit tests for base client Tool classes
fixed unit tests using long ints for py3k
fixed option description for bcfg2-crypt passphrase option
better error message when rendering a template that failed to parse
Metadata: prevent overwriting of clients.xml with xinclude
Frame: Sort unmanaged entries

Thanks Chris for the lambda magic.

Signed-off-by: Sol Jerome <sol.jerome@gmail.com>
Packages: fixed overzealous deduplication of packages that removed essential and group packages