More experimentation with the blog.
Added About OMBU section and RSS subscription link.
Corrected span count of pagination div.
Added link on blog article page to return to blog index.
For now, just show the tags of blog articles as text; not links to browse by tag.
Position About OMBU block absolutely on non-mobile displays.
Restyled the logo and its containers so that the centered image will align with Bootstrap's fluid spans.
Moved markup for the blog title and About/RSS block to a partial to DRY up the blog index and article views.
Changed content order & styles for About/RSS block so that blog content comes first.  Also added fixed positioning of block for wide displays.
Added FontAwesome RSS icon for blog subscription link.
Refs #3591: created visual treatment for horizontal rule between articles.
Added responsive styles for aside containing post info.
Refs #3589: added visual treatment to About OMBU block.
Refs: #3592: Made minor tweaks to markup position and styles for DISQUS comments.