Use application/json as default content type for POST

[robertjd]

We are currently using application/x-www-form-urlencoded as the default value for STORMPATH_CONFIG.FORM_CONTENT_TYPE. This is a leftover from the initial version, and this should now be changed to application/json. This should be a major version issue because some may have configured their body parsing middleware to only look at form encoded posts, so switching the content type will break their application.

In the meantime, you can manually configure the library like so:

angular.module('myapp')
  .config(function(STORMPATH_CONFIG){
      STORMPATH_CONFIG.FORM_CONTENT_TYPE = 'application/json';
  });