Sync the configuration.xml example with current Studio code

This commit updates the configuration.xml example to be in sync with
current Studio code, namely these changes done lately:

  * We expose image type and version in the API (bnc#790914).
  * Users now usually have a UID.
  * We implemented SLMS integration in Onsite.
Merge pull request #54 from dmajda/fix-configuration-xml-example

Sync the configuration.xml example with current Studio code