UI matching in detail view to iOS version

* ListView -> LinearLayout for categories
* Add labels for fields
* Cool transparent rectangles!
* Padding adjustments...
* Darken image when scrolling detail panel up
* Placeholders for empty desc, license fields

Change-Id: I0e4c4348e741af3560d455ee4b793c2743626fbf
Merge "UI matching in detail view to iOS version"