For all manually-created images PNG have been kept.
- rename all icon attrs to have a `ic_` prefix
- always use `_24dp` icons, because there is no real difference, since they are vector drawables
- always use the original name found on material.io for icon drawables, as to not create confusion and possibly duplicates. Icon names can still be different from real drawable names, though I have made some of them compliant to this or maybe more meaningul.
- remove duplicate `getIconByAttr()` in ThemeHelper (use `resolveResourceIdFromAttr()`
- use standard icons for `expand_more` and `expand_less` instead of triangles
- use `play_button_outline` instead of custom PNG as play button in VideoDetailFragment (questionable, as there is no shadow anymore)
Now only the subscriptions from the selected group by the user will be
loaded.
Also add an option to decide how much time have to pass since the last
refresh before the subscription is deemed as not up to date. This helps
when a subscription appear in multiple groups, since updating in one
will not require to be fetched again in the others.
- Introduce Groupie for easier lists implementations
- Use some of the new components of the Android Architecture libraries
- Add a bunch of icons for groups, using vectors, which still is
compatible with older APIs through the compatibility layer
-Added UI for watch history and most played fragments.
-Added stream state table for storing playback timestamp and future usage.
-Enabled playlist deletion.
