Some fixes and additions + update to API17 (InsertHelper deprecated)

Changes:
- Updates target sdk version to 17
- Removed use of InsertHelper because it is deprecated now
- Fixed not saving progress (at least it wasn't on my Nexus 4)
- Fixed not calculating the progress in the right way when in series view mode
- Added "Mark Read" as Contextmenu Item (able to use on single comic and series)
- Made the Contextmenu Item "Reset Progress" able to operate on a whole series