added small today study overview to DeckPicker, changed fmtTimeSpan to actively use unit like the desktop version
recreate TodayMiniStatistics on sync
the first statistic tab shown now is dependent on whether something has been learned (today stats will be shown) or nothing has been learned (forecast will be shown)
changed theme for statistics to modified variant for better radio button compatibility on smaller devices, fixed typos in class and method names
changed position of small today statistics to bottom of screen to prevent overlap from listview when deck list is larger than the screen.
Merge pull request #452 from trashcutter/stats_small_things

Today mini Statistics
Bumped version to 2.3alpha6
@branch-specific