Renames asset-service module to test-service
Adds authoring and editor modules back to project

They were removed about 4 months ago:
https://github.com/quiaro/studio3/tree/d7cd9dd9d7371430f111c3e7bf67b231083d026e
Loads language files as json, not as js

This way they can (and should) be treated differently than js files
during the build process
Updates code in authoring module to make it work with current codebase
Request language files as .json, not as .js
References documentation in wiki