improve documentation

app/services/changelog-parser.js

 import Ember from 'ember';
 
 // TODO: update cytoscape instead of complete rerender
+/**
+ * The changelog parser takes a changelog (as a plain JS object) and updates the internal
+ * state of the Ember Data store automatically. Supports CREATE, UPDATE, DELETE and APPEND operations
+ *
+ * @class ChangelogParserService
+ * @extends {Ember.Service}
+ */
 export default Ember.Service.extend({
     store: Ember.inject.service(),
+
+    /**
+     * Parse a list of changelogs
+     * @param  {Array} changelogs List of changelogs, as plain JavaScript objects
+     * @method parse
+     * @public
+     */
     parse(changelogs) {
         this.debug('store', this.get('store'));
         this.debug('parsing changelogs', changelogs);
         changelogs.forEach(this.parseSingle.bind(this));
     },
+
+    /**
+     * Parse a single changelog
+     *
+     * @param  {Object} changelog changelog as plain JavaScript object, see backend documentation for data structure
+     * @method parseSingle
+     * @public
+     */
     parseSingle(changelog) {
         const operation = this.get(`operations.${changelog.operation}`);
         if(!operation) {

app/services/changelog-queue.js

 import Ember from 'ember';
 
+/**
+ * Stores changelogs which were received via ChangelogStreamService and applies the {ChangelogParserService} if triggered externally
+ *
+ * @class ChangelogQueueService
+ * @extends {Ember.Service}
+ * @uses ChangelogStreamService
+ * @uses ChangelogParserService
+ */
 export default Ember.Service.extend({
     changelogParser: Ember.inject.service(),
     _private: {

app/services/visualisation-events.js

@@ -8,7 +8,6 @@ import Ember from 'ember';
  *
  * @class VisualisationEventsService
  * @extends {Ember.Service}
- * @public
  */
 export default Ember.Service.extend(Ember.Evented, {
     /**