Removed the license and the version info from the compact view, and
showed the description instead. The installed status, and whether the
app can be updated or not (but not which version can be updated to) is
now shown via little icons on the right hand side of the list view.
Also refactored adapters to allow different views for
Available/Installed/Updates tabs. This is because I didn't want the
"installed" status icon in the installed tab, and neither the
"installed" nor the "updates" icon in the "updates" tab.
The adapters were moved to the "views" package, because I needed to add
three new classes and they started to clutter the list of *.java files.
