Tune the tab switch performance

1. Create adpater when data init done
2. Delay setAdapter when first visit fragment and setdata
3. Delay setData when tab view switch and the fragment visited at first
time
4. setOffscreenPageLimit(3);
5. set isShow = false  when NewsView onStop to fix webview can't reload
issue when setOffscreenPageLimit < 3
Modify the GroupAdpater

1. Modify the GroupFragment and adpater
2. Fix StatisticsFragment status issue
Add progressbar for fragment