https://fedorahosted.org/sssd/ticket/1992

dyndns test will crash with this patch

This patch implements some unit tests for the recent enhancements to
libsss_idmap.

https://fedorahosted.org/sssd/ticket/1648

Adds another expansion in the printf format that allows the user to use
the domain flat name in the format.

--removed duplicated test-io
--reusing library libsss_test_common in other tests
--cmocka test sss_nss_idmap-tests was moved to cmocka dir
--moved leak_check.c to libsss_test_common
--moved common_tev.c,common_dom.c to libsss_test_common
  (leak_check.c,common_tev.c,common_dom.c) are test framework independent

The dyndns init function was starting the timer even if the updates were
set to False. This patch splits the init of dynamic updates and the
timer into two functions so that the back end can start the updates
separately from reading the options.

The tests_set_cwd() function was called twice in the dyndns unit test.

This options is mostly provided for future expansion. Currently it is
undocumented and both IPA and AD dynamic DNS updates default to
GSS-TSIG. Allowed values are GSS-TSIG and none.

https://fedorahosted.org/sssd/ticket/1831

Adds a new option that can be used to force nsupdate to only use TCP to
communicate with the DNS server.

This new options adds the possibility of updating the DNS entries
periodically regardless if they have changed or not. This feature
will be useful mainly in AD environments where the Windows clients
periodically update their DNS records.

This patch introduces new options for dynamic DNS updates that are not
specific to any back end. The current ipa dyndns options are still
usable, just with a deprecation warning.