Add do_shortcode filter to the_excerpt.

The blog and archive use the excerpt in lieu of the content to eliminate loading of so much content on one page. This filter allows shortcodes (like [gallery]) to execute within the_excerpt.
Fix video width and margin.
Remove background colors from post formats.

This is something that can be implemented for custom sites or possibly and option added in later, but for now it is not something I want included in the theme.
Change featured image size to main-featured.
General code cleanup.

*Salute*
Remove the filter that removes the item from the content.
Change heading font family.
Spruce-up block quotes.