Replace twitter with official/custom widgets
Fade out and shorten links in sidebar tweets
Styles and no-force-wrap for sidebar tweets
Fix broken video resizing from last upstream merge
Don't pass (unused) width/height for youtube
Strip email subject prefixes from RSS titles

- fix typo for replacement of '>' entity
- use separate div block for rss description
Rearrange sidebar aside styles
Add missing table styles for borders etc.