setools: APOL Add default_objects and CIL policy namespaces tabs

Add support for default_object rules and displaying CIL namespaces
with any users, roles, types, classes, booleans, sens & cats declared.

Fixed generating file index on File Contexts tab where it would hang
forever if broken links/files (mainly when generating indexs for Android)

Also enhanced the previous features in te_rules and types tabs.

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>