Merge tablet and phone stats layouts. Tablets will still use a two column layout in landscape.

Most of this is code removal, but I also tweaked some of the margins so that elements line up better with one another.
Merging @daniloercoli’s patch for #305 in for clearing data when switching blogs. Added two more fragment replacements for the new top posts and country views fragments.
Merge remote-tracking branch 'origin/release/2.5.1' into issue-308

Tablets and small screens aren't handled differently

Conflicts:
	src/org/wordpress/android/ui/stats/StatsActivity.java
Swap positions of Top Posts and Pages and Country Views on for phone screens. Left the two column tablet layout the same to match the default appearance on WordPress.com. Props @nbradbury
Merge pull request #309 from wordpress-mobile/issue-308

Put all stats fragments on the same layout, using same layout as tablet UI. Fixes #308