fix(compiler): revert 8611ebe6 - calling \$digest after linking

Change introduced by me in 8611ebe6 results in considerable inefficiencies when the compiler
and linker is used from within a widget, in which case, we call $digest unnecessary since it
will be called by the $apply which called the directive/widget in the first place.

There are only two places when the extra $digest call can be useful - when manually bootstrapping
the app or in tests. However even in tests this behavior can result in unwanted results (especially
when ng:controller is involved). So it is better to leave it for the developer to call $digest
when it is really needed.

docs/content/guide/dev_guide.bootstrap.manual_bootstrap.ngdoc

@@ -17,7 +17,7 @@ explicitly.
   <script src="http://code.angularjs.org/angular.js"></script>
   <script>
      angular.element(document).ready(function() {
-       angular.compile(document)();
+       angular.compile(document)().$apply();
      });
   </script>
 </head>