Implement a test for new dnszone-find option --forward-only.
Fix example for reverse zone (zone was not fully qualified and
DNS plugin would forbid adding PTR records).

https://fedorahosted.org/freeipa/ticket/1473

The DNS record plugin does not support modification of a record. One
can only add A type addresses to a DNS record or remove the current
ones. To actually change a DNS record value it has to be removed and
then added with a desired value.

This patch adds a new DNS plugin command "dnsrecord-mod" which enables
user to:
 - modify a DNS record value (note than DNS record can hold multiple values
   and those will be overwritten)
 - remove a DNS record when an empty value is passed

New tests for this new command have been added to the CLI test suite.

https://fedorahosted.org/freeipa/ticket/1137

Bind cannot load a zone if any of its name server records is not
resolvable.

https://fedorahosted.org/freeipa/ticket/838

Error out when deleting a nonexistent DNS record

Also fixes the DNS unit tests.

https://fedorahosted.org/freeipa/ticket/816
https://fedorahosted.org/freeipa/ticket/829

The changes include:
 * Change license blobs in source files to mention GPLv3+ not GPLv2 only
 * Add GPLv3+ license text
 * Package COPYING not LICENSE as the license blobs (even the old ones)
   mention COPYING specifically, it is also more common, I think

 https://fedorahosted.org/freeipa/ticket/239

- Skip the DNS tests if DNS isn't configured
- Add new attributes to user entries (displayname, cn and initials)
- Make the nsaccountlock value consistent
- Fix the cert subject for cert tests

Ticket #36
Ticket #450