Reader list now uses a staggered grid in landscape
Changed card elevation, adjusted horz spacing in portrait mode
Adjusted horz & vert spacing in landscape mode
Changed old reader_list_margin_xxx values to only be used in detail view
Staggered grid is now always used on large tablets (not just in landscape)
Staggered grid no longer used in landscape if device isn't xhdpi or better.
Work around RecyclerView bug that causes canScrollVertically() to return false prematurely, which causes swipe-to-refresh to appear when scrolling up
Minor tweak to decoration margins
Merge branch 'feature/reader-staggered-grid' of https://github.com/wordpress-mobile/WordPress-Android into issue/reader-cardview-spacing
Adjusted card spacing to match detail spacing
Merge branch 'release/3.5' of https://github.com/wordpress-mobile/WordPress-Android into issue/reader-cardview-spacing
Merge branch 'release/3.5' of https://github.com/wordpress-mobile/WordPress-Android into issue/reader-cardview-spacing
Merge branch 'release/3.5' of https://github.com/wordpress-mobile/WordPress-Android into issue/reader-cardview-spacing
Merge pull request #2019 from wordpress-mobile/issue/reader-cardview-spacing

issue/reader-cardview-spacing