Improve `matrix` object

Since it basically has the same properties that the `block-list` objects we can make proper use of the DRY principle and @extend it.
Made watch.sh executable on unix

`chmod +x watch.sh`
Add missing 'lap-and-up' and 'desk-wide' to 'hide' helper classes
Merge pull request #129 from danshearmur/watch-execuatble

Made watch.sh executable on unix
Shorter clearfix for IE8+

removed z-index for IE6/7
removed :before as it is not necessary for IE8+
Merge pull request #133 from maxhoffmann/patch-1

Shorter clearfix for IE8 and above
Remove trailing whitespace.
Updated inuit.css documentation link in README
Merge pull request #142 from kamilogorek/patch-1

Updated inuit.css documentation link in README
Update inuit.css/generic/_widths.scss

just fix a little misspelling
Merge pull request #143 from aastudio/patch-1

Fix typo in comment
Switched base font-family to use a variable

The base font-family is a design choice. By using a variable we can set
it once and avoid having to override it
Merge pull request #141 from javierav/whitespace

Remove trailing whitespace
Merge pull request #130 from bewildergeist/fix/hide-helpers

Add missing 'lap-and-up' and 'desk-wide' to 'hide' helper classes
Add float none helper
Add text helper comment
Add margin and padding helpers
Improve go class
Improve hidden content helper
Merge remote-tracking branch 'kevva/fix/matrix' into fix/matrix

Fixes #112