Updated SASS grid

[mobywhale-chan]

Changes:

• Give all units a padding-left and use .line {margin-left: -$gutter} to offset the extra padding-left. This will allow things to line up.
• Changed IE7 to use padding-left as well but just recalculate the width of the unit.
• Use different clearfix for .lastUnit and .line
• Removed .unit:last-child as this causes problems if the line only has one unit but you want the unit to be a specific size e.g. size2of12. Having :last-child will cause the unit to take up all the space.
• Updated grid_doc.html.
• Removed @import clearfix-me from various files as it was causing inheritance issues. Added it to screen.scss
• Also removed @import variables from various files as it was getting repeated in compiled css.

[stubbornella]

I feel like we should remove the css output from github until we are ready to release an alpha of the sass ooccss project. And then we should remove things like debug output. We can do that in another commit.

[mobywhale-chan]

Yeah I agree we should remove the css output and the debug output. Will de-commit it in another commit.