ipaclient: move install modules to the install subpackage

The ipa_certupdate, ipachangeconf, ipadiscovery and ntpconf modules depend
on ipaplatform.

Move them to ipaclient.install as they are used only from the client
installer.

https://fedorahosted.org/freeipa/ticket/6474

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

client/ipa-certupdate

@@ -18,6 +18,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-from ipaclient.ipa_certupdate import CertUpdate
+from ipaclient.install.ipa_certupdate import CertUpdate
 
 CertUpdate.run_cli()

client/ipa-client-automount

@@ -40,12 +40,12 @@ from six.moves.urllib.parse import urlsplit
 # pylint: enable=import-error
 
 from optparse import OptionParser  # pylint: disable=deprecated-module
+
+from ipaclient.install import ipachangeconf, ipadiscovery
 from ipalib import api, errors
 from ipalib.install import sysrestore
 from ipalib.install.kinit import kinit_keytab
 from ipapython import ipautil
-from ipaclient import ipadiscovery
-from ipaclient import ipachangeconf
 from ipapython.ipa_log_manager import root_logger, standard_logging_setup
 from ipapython.dn import DN
 from ipaplatform.constants import constants