Move to Angular 1.5

This has been reasonably well tested, but further testing should be done on staging.

Also optimizes avatar handling to use a constant size and not 404.

Fixes #1434

static/js/pages/landing.js

@@ -21,7 +21,7 @@
 
     UserService.updateUserIn($scope, function(user) {
       if (!user.anonymous) {
-        $location.path('/repository');
+        $location.path('/repository/');
       }
     });