text-rendering: optimizeLegibility on body
Compressed/minified combined.out.css
Switch to optimizing for speed in text rendering

Saw no improvements in Firfox on Android (which becomes blurry when scrolling)
but there are known performance issues with optimizing for legibility.
Use http_response_code instead of header on invalid request
Improved a few functions & added documentation

Use array_walk() instead of foreach() making $selectors safe in
get_recent_posts(). Add the "`" when joining.

Made several variable names more descriptive.

Broke long lines of code (chained) up into multiple lines
Improved get_all_tags()