Optimized Semantic Grid Mixins

Removed some duplicate code by making the hybrid mixin include  the
column mixin. Also moved the columnconfig extend call outside the
conditionals.
Merge branch 'hotfix/2.4.8'
Merge branch 'master' of https://github.com/sashasklar/Gumby into sashasklar-master
compiled for testing
Merge branch 'sashasklar-master' into develop

Conflicts:
	css/gumby.css