Update pseudo-elements to double-colon syntax

This resolve #165.
Grammar tweaks to index
Tweak to basic grammar
Strip unnecessary font-family rule
Fixed the link to the troubleshooting page.

Previously linked to the main GitHub repository page, now it links directly to the troubleshooting page in the wiki.
Bump gulp-cache to 0.2

Changelog available here:
https://github.com/jgable/gulp-cache/compare/3b44956e60b4a96905ade5391f730f03604ae27c...0.2.0
Fixes #174 - moves demo classes to styleguide
Move demo gray to sass utils
Fix missing pygments highlighting
Strip unnecessary link in styleguide
Close GH-171: Livereload breaks on jshint error(s) when running `gulp serve`. Fixes #169
gulpfile - don't need `init` anymore
Give serve preference to files in .tmp

From my testing, the browserSync server prefers files in app over files in .tmp when they have the same name. .tmp files should be preferred, since any file in .tmp has been processed in some way (e.g., a main.css file that's autoprefixed into .tmp, or an index.html that contains some templating that's precompiled into .tmp).
Removed reference to BrowserSync running instance
readme - link to latest release
Handle error event generated by jshint fail reporter

Closes #194