Update _about.css.scss
Fix fa build path
remove bootstrap
Fix content of index page
Fix UI bugs
Improve UI
Optimize images and update text
Fix font awesome again
Merge remote-tracking branch 'up/master'

Conflicts:
	source/localizable/about.cn.html.haml
	source/stylesheets/_about.css.scss
	source/stylesheets/_index.css.scss
	source/stylesheets/_nav.css.scss