preferences: clearer texts, dependency;
fix: notification icon is updated on changing icon visibility;
fix: notification icon is shown after App info launch in preferences;
fix: leaked resource in preferences;
fixed full log crash (app name retrieval via dedicated class);
db backup and restore: show progress dialog;
suppress deprecated warnings for PreferencesActivity;
fixed session=null crash on db upgrade;
less warnings in MainActivity;
wifi view: showing "connecting" and "disconnecting" states;
hide duplicate wifi events;