Additions to enable navigation highlighting

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 - Added AppCtrl to <html> tag.
 - Added AppCtrl to controllers.js.
 - Defined $scope.isActive function that takes a viewLocation and returns a boolean if it is the same as $location.path().
 - Added ng-class="{ active: isActive('/viewname')}" to ul.menu > li items.
 - Added css class .menu > li.active to highlight active navigation item with bold font.

 I hope this commit will be accepted as it is a natural feature extension that almost everyone wants to use. If a router is demonstrated with navigation and partials highlighting the current active navigation item makes totally sense to me.

 Cheers Bijan