No longer hiding embeds when JS is disabled
Embeds now use min-height to avoid clipping Instagram embeds (which aren't 16:9)
Reverted previous min-height change, caused problems with YouTube and other embeds
Added ReaderIframeScanner to enable resizing iframes, moved HTML routines from ReaderImageScanner to new ReaderHtmlUtils.
Optimized image/iframe parsing
 Code style tweaks, also now setting IFRAMES to include frameborder='0' allowfullscreen='true' allowtransparency='true'
Removed tbl_tag_updates, no longer storing before/after fields, no longer passing &after param when requesting newer posts
Remove backfill when updating posts - it didn't work well and wasted bandwidth
Removed UpdateResultAndCountListener
Simplified logic for reporting when posts are updated
Removed irrelevant comment
Removed unused imports
Posts in "Blogs I Follow" are no longer purged when followed blogs change
Rewrote logic for purging posts to discard older posts on a per-tag basis
Code cleanup
Modified UpdateResult to differentiate between when there are new posts/comments and when there are changed posts/comments.
Smarter logic for determining when downloaded posts are new or changed
Response from updating posts in a blog now handled in separate thread
Consolidated response handling when updating posts with a specific tag and updating posts in a specific blog
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into issue/1938-reader-update-logic