[Framework] Bring in changes from sandbox

Bring in changes from 'sandbox' branch. These include:

* Reconfiguring require's baseUrl such that relative
  paths work as expected in define call dependencies.
  Previously this only worked as expected in the
  framework bundle, since data-main points there.
* Add support for a 'constants' category of extension,
  to define application constants from bundles. This
  allows services to treat static values (such as
  persistence URIs) as injectable dependencies.
* Various assurances that properties from extension
  definitions will be exposed upon resolved
  implementations, even after partial construction.

WTD-572.

platform/framework/src/Main.js

@@ -80,6 +80,9 @@ define(
             initializer.runApplication(Constants.BUNDLE_LISTING_FILE);
         }
 
+        // Reconfigure base url, since bundle paths will all be relative
+        // to the root now.
+        requirejs.config({ "baseUrl": "" });
         injector.invoke(['$http', '$log', initializeApplication]);
     }
 );