Improve Card: now the content can be set in the XML-layout
Add offline info card

This card is shown if there is no network connection and the record is
not in the database.
Merge pull request #256 from d-sko/dv_loading_indicator_2

Follow up for #250
Replace listview with expandable listview (DetailView)
Fix automatic scrolling bug (DetailView)
Add indicator to the headers (DetailView)
Add viewholders to make relations smooth (DetailView)
Change the green card color (Colors)