Api client updates

* Refactored RAML client generation
  * Magic `authenticate` method - automatically selects authentication option
  * Option injection with every request type
  * Default options -`baseUriParameters`, `uriParameters`, `headers`, `query`, `body`, `proxy`
  * `mediaTypeExtension` support - no more using it as a function!
* No longer completes object literal property names
* No longer resets to notebook view when switching notebooks in editor view
* Improved tests