Relative JS/CSS include paths for easier local testing.

This was probably hard coded at one time so that the site would look
right when scraped. Not sure why I wanted to help scrapers at some
point...
Converted a few more absolute URLs to relative.
Updated script references to match new structure.
Moved plugins.min.js to a new location and included comment-reply.

Since almost every pageview is for an individual post, it doesn't make
sense to keep comment-reply separate from the rest of the vendor/plugins
bundle. Rolled it in for simplicity/performance.
Moved local fallback jQuery to new location.
Trying out Grunt for building the site's JS.
They don't pay me enough for this.
Relative URL for the +1 script.