Create "Date and time settings" page

There was a Date and time page in the GUI. Enhanced it to
display the BMC time and added it to the menu so users
could navigate to it.

Future things planned for this page:
Setting the time, time mode, and time owner.
Adding a NTP server.

More information can be found in the time manager README:
https://github.com/openbmc/phosphor-time-manager/blob/master/README.md

Tested: See the BMC time.
Change-Id: Ia3ac2385cb45ec8009ed6df0899c3410fe18ef64
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/app/common/directives/app-navigation.html b/app/common/directives/app-navigation.html
index 8c8f88a..36a57d5 100644
--- a/app/common/directives/app-navigation.html
+++ b/app/common/directives/app-navigation.html
@@ -103,9 +103,11 @@
 			<a href="#/configuration/network" tabindex="14" ng-click="closeSubnav()">Network settings</a></li>
 		<li ng-class="{'active': (path == '/configuration' || path == '/configuration/firmware')}">
 			<a href="#/configuration/firmware" tabindex="15" ng-click="closeSubnav()">Firmware</a></li>
+		<li ng-class="{'active': (path == '/configuration' || path == '/configuration/date-time')}">
+			<a href="#/configuration/date-time" tabindex="16" ng-click="closeSubnav()">Date and time settings</a></li>
 	</ul>
 	<ul class="nav__second-level btn-users" ng-style="navStyle" ng-class="{opened: (showSubMenu && firstLevel == 'users')}">
 		<li ng-class="{'active': (path == '/users' || path == '/users/manage-accounts')}">
-			<a href="#/users/manage-accounts" tabindex="16" ng-click="closeSubnav()">Manage user account</a></li>
+			<a href="#/users/manage-accounts" tabindex="17" ng-click="closeSubnav()">Manage user account</a></li>
 	</ul>
 </nav>