[WIP] Offline Support

[WIP] DO NOT MERGE IT YET
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I've integrated ORMLite for offline support. Also I've made a few changes to the existing model classes to fit with ORMLite. 

TODO
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- [x] DB Integration
- [x] Save the downloaded objects to the db and load it when the fragmented is loaded.
- [ ] Refresh methods. 

For the refresh the data, we have a few options 
- "Refresh" Action Menu icon 
- Chris Banes Actionbar PTR
- [SwipeRefreshLayout](https://developer.android.com/reference/android/support/v4/widget/SwipeRefreshLayout.html) . Basically, the same idea as above but built-in support.

(Sorry for sending the PR from 'master'. Will send the the future PR from feature-as-a-new-branch branches)