Fix license in some Web UI files

Modified web ui files had incorrect GPLv2 headers instead of GPLv3 ones.

All of the affected code is of FreeIPA origin.
Allow kernel keyring CCACHE when supported

Server and client installer should allow kernel keyring ccache when
supported.

https://fedorahosted.org/freeipa/ticket/4013
ipa-client-install: Always pass hostname to the ipa-join

The ipa-client-install script and ipa-join use different methods
of resolving the hostname, the former uses gethostbyaddr() call,
while the latter reads the "uinfo.nodename".

This can result ipa-client-install failures in case of broken PTR
records.

https://fedorahosted.org/freeipa/ticket/4027
test_webui: Allow False values in configuration for no_ca, no_dns, has_trusts

The driver only checked if the corresponding value was in the config, so
    no_dns: False
had the same effect as
    no_dns: True

Change the check to take the value into consideration.

This makes false-y values like False (from YAML) and empty string
(from environment) work as if the value was not specified.
ipa-cldap: Cut NetBIOS name after 15 characters

The CLDAP DS plugin uses the uppercased first segment of the fully
qualified hostname as the NetBIOS name. We need to limit its size
to 15 characters.

https://fedorahosted.org/freeipa/ticket/4028
trust: fix get_dn() to distinguish creating and re-adding trusts

Latest support for subdomains introduced regression that masked
difference between newly added trust and re-added one.

Additionally, in case no new subdomains were found, the code was
returning None instead of an empty list which later could confuse
trustdomain-find command.

https://fedorahosted.org/freeipa/ticket/4067
Increase stack size for Web UI builder

Web UI build fails on some architectures or configuration due to
StackOverflow. This patch increases the stack size to solve it.

512k is usually enough but we encountered fail on ppc64 even with 2m,
therefore the 8m. The build is single threaded so it shouldn't waste
much memory.
Increase Java stack size on PPC platforms

Wit the default stack size, rhino segfaulted on PPC platforms.

https://bugzilla.redhat.com/show_bug.cgi?id=1040576