Initial (har) import of all css properties

Properties exported from web platform docs:

http://docs.webplatform.org/Special:Ask/-5B-5BCategory:CSS%20Properties-5D-5D/format=json/offset=0/link=none/headers=hide/syntax=basic/prettyprint=yes/
Add the semantic-wiki export URL
gitignore
Generate the initial.css file using grunt and Web Platform docs