* Saving to SD working
* Rename imagePath to uri
* Handle android < 21
* Minor changes
* Separate downloader from the manager. Optimize folder lookups
* Persist downloads across restarts
* Fix for #511
* Updated ReactiveNetwork. Add some documentation
* More documentation and minor fixes
* Handle persistent notifications. Other minor changes
* Improve downloader and add documentation
* Rename pageNumber to index in Page class
* Remove unused methods
* Use chop method
* Make sure dest dir is created
* Reset downloads dir preference
* Use invalidate options menu in download fragment and fix wrong condition
* Fix empty download queue after application restart
* Use addAll method in download queue to avoid too many notifications
* Inform download manager changes
