Earlier setup of Lumberjack

Should give me better logs during initializing
fix crashes where collection view reloads but objects have vanished

Crashlytics Issue #8
https://www.fabric.io/passions/ios/apps/ch.taennler.simon.passions/issues/5485743665f8dfea154750e1
properly check if on screen
directly check ivar to avoid cache recovery
Passions own Last.fm key
defensive cache clearing
complete fetching when no artists found
proper isFetching update
improve session handling and button update
protecting clearCaches in didReceiveMemoryWarning
better fit long text into cells
artists with long names
table view gets reloaded if isFetching
catch a few more errors
clearer grouping
hudMsg -> loadingHudMsg
loading hud with a property
Info Msg when no artists
clear caches before preparing them
refresh on viewWillAppear when no objects