now only the corresponding tab fragment is refreshed when themes are fetched.
Also prevents user to pull to refresh in search view.
fix #1147
Merge branch 'develop' into issue/1147-themes-first-load-progress-bar
use DisplayUtils.getDisplayPixelWidth instead of display.getWidth()
cleanup and code style
Merge branch 'develop' into issue/1147-themes-first-load-progress-bar
fix empty tab themes after first refresh
Merge pull request #1280 from wordpress-mobile/issue/1147-themes-first-load-progress-bar

fix #1147 progress bar is now visible on themes screen first load.