Added container and gutter for b6

Author: dariusrosendahl

sass/base/variables.scss

@@ -36,6 +36,7 @@ $container-b2: 100%;
 $container-b3: 744px;
 $container-b4: 996px;
 $container-b5: 1224px;
+$container-b6: 1400px;
 
 /* Default margin, padding, gutter */
 $padding-default: 	12px;

sass/layout/grid.scss

@@ -16,6 +16,7 @@ $grid-gutter-b2: 12px;
 $grid-gutter-b3: 12px;
 $grid-gutter-b4: 12px;
 $grid-gutter-b5: 12px;
+$grid-gutter-b6: 12px;
 
 /* Grid basis */