Add ability to save and restore current card index in pager.
Change content provider batch access to use transaction.
Add deck shuffling task.
Add cards order resetting task.
Modify content provider to follow current card index usage.
Modify cards pager activity to use loaders and sort order properly.
Fix inspection warnings.
Merge branch 'cards-sort-order' into content-providers
Change provider declaration to be not exported.
Refactor content provider.
Refactor UI code.
Add copyrights.
Fix formatting.