Issue #139: remove util/Config (and then util/Map)
- Removed util/Config and util/Map (because only util/Config depended on it)
  and unit tests
- Side effect: mvc/Model depended on Config, but only to get the apiRoot in
  Model#getApiURL. We now do that in project-specfic Service classes, so I
  removed that method.
- Side effect: mvc/Application depended on Config, which it passed to
  Application#beforeInit for subclasses to override. My line of thinking is
  that subclasses can load this themselves.