libsemanage: add back support for semange_set_root using the new source policy infrastructure

Removed in commits:
- Revert "libsemanage: introduce semanage_set_root and friends"
- Revert "libsemanage: Alternate path for semanage.conf"
- Revert "libsemanage: Use default semanage.conf as a fallback"

Signed-off-by: Steve Lawrence <slawrence@tresys.com>
8 files changed