1. add a view fragment for category list
Merge branch 'tv' of https://github.com/abelearth/fdroidclient into tv
Merge branch 'tv' of https://github.com/abelearth/fdroidclient into tv
1. Delete unuse improt;
2. Add a function to focus search icon by pressing right key.
1. Use ViewPager to set view from CategoryListFramgment to AvailableAppsFragment;
2. Delete drop-down menu form AvailableAppsFragment;
3.Fix display bug of appdetails framgent: make the category text clear;
4.Avoid categorylist.xml WARNING.