Improve ordering of styles & scripts

wp_head will probably output CSS first, and JS second, so call
it after our own CSS but before our JS to get the right overall
ordering.
Trim trailing whitespace & fix HTML whitespace
Upgrade JQuery + UI
Add fancier blockquote styling
Improve blockquote formatting
Add broken link styling to external CSS
Add styling to the post author's comments
Remove some inline styling
Major cleanup of CSS
Don't jump to the top of the page when switching styles

The previous method used <a href="#" ...> for the styleswitch
links, which caused the jump. This method appears to be a
link, but isn't (we don't need it to be since JS does the work).
Remove unneeded padding/margin for <code>
Better styling for syntax-highlighted <pre>
Remove unneeded CSS
Upgrade jQuery & jQuery UI