correct order for css3 properties with vendor prefix

If you list the vendor prefix after the actual property, the vendor prefix will override and be the property that renders.

details: http://css-tricks.com/ordering-css3-properties/
Add overview of :extend functionality
Fix typo in the variable example
Merge pull request #101 from tmccombs/patch-1

Add overview of :extend functionality
Merge pull request #99 from jakob-stoeck/master

correct order for css3 properties with vendor prefix
fix :extend all functionality example
Merge pull request #102 from amatellanes/master

fix :extend all functionality example
Ignore .DS_Store files
Remove unused images and losslessly compress the rest.

Also, add forkme_left_red.png in the repo and optimize it.
Add alt text and image dimensions for download-button.png.
Remove type="text/javascript".

This is no longer needed for HTML5.
Remove trailing spaces and extra newlines.
Include less.js after all the css files.
Use https for the Github links.
Remove the unused Twitter script.
Remove unit from zero.
templates/layout.rhtml: Minor html5 fixes.
Include html5shiv.js for older browsers.
Fix validation errors.