new feature: links associated with apps.

press the app icon on the main screen and you're taken to a links activity. you can add and remove links there.
added more debug logging for skipped apps
added description and changelog to AppInfo
fixed typo, columns were not added when creating from scratch
get last market update date
added AppDetails to store description, etc.
linked Links to AppDetails with FK
Merge pull request #351 from nelenkov/links-page

Added AppDetails table/class; linked Links to AppDetails with FK
Upstream #352 add appinfo page with description, version, changelog, last store update date, links.
GH #352 redesigned links (to be renamed appinfo) page
GH #352 renamed links to appinfo.
Merge pull request #353 from therealdpk/appinfo

GH #352 redesigned links page
merged dev
removed unused import
Merge branch 'dev' into links-page
Merge pull request #360 from nelenkov/links-page

merged dev fixes for v2.4.3
moved Add back to action bar
added app icon, moved Play Store button
Merge pull request #374 from nelenkov/links-page

Redesign slightly
merged appinfo branch