Refactor selinuxenabled check

Ticket: https://fedorahosted.org/freeipa/ticket/4571
Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>
test_service_plugin: Do not lowercase memberof_role

This adjusts the test for the change in commit 792c3f9c8c65e24953241247a242490c8fb32492

Related ticket: https://fedorahosted.org/freeipa/ticket/4192
Add Gabe Alford and Thierry Bordaz to .mailmap
Add additional backup & restore tests

https://fedorahosted.org/freeipa/ticket/3893
backup/restore: Add files from /etc/ipa/nssdb

Add files from /etc/ipa/nssdb (IPA_NSSDB_DIR), which now used
instead of /etc/pki/nssdb (NSS_DB_DIR).
The old location is still supported.

https://fedorahosted.org/freeipa/ticket/4597