function getCollName(coll) {
        return coll.name;
      }
(Changes API) : takes all the changes stored in each
collection and creates a single array for the entire database. If an array of names
of collections is passed then only the included collections will be tracked.

@param {array=} optional array of collection names. No arg means all collections are processed.
@returns {array} array of changes
@see private method createChange() in Collection
@memberof Loki