Renamed variables file to better integrate with other SCSS projects

Now you can drop in Chassis to an existing SCSS project without having
to mes around with merging separate variable files together.
Newer clearing solution for .row, adjusted comments

Added a new CSS solution for float clearing; this rule works best best
with newer browsers so the old solution has been left in comments if
you need it.
Merge branch 'dev'
Added license

Added a license for Chassis
corrected outdated variables import
Better comments, new media query for large grid

Comments are now more helpful.
The large grid media query has been updated to 1200px instead of 1280;
thanks to http://1200px.com/ for the idea.
Better grid variables

New grid measurements have been created so that columns now have a
default padding.
New measurements

Added default padding for columns, and removed the annoying padding
rows used to have.
Cleaned out some cruft code.
New measurements, new max-width

New max-width for large rows; thanks to http://1200px.com/ for the idea.
Added default padding for columns, and removed the annoying padding
rows used to have.
Cleaned out some cruft code.
Updated demo

Updated the demo and its styles to better show off the grid sizes,
margins and padding.
updated CSS

updated based on the new SCSS
update gitignore
update gitignore
delete .sass-cache
Merge branch 'dev'