Make line-height optional in font-size mixin
Add headings mixin
Merge branch 'feature/mixins' into v5.0
Remove Batch
Merge branch 'fix/batch' into v5.0
Merge branch 'v5.0' into feature/submodule

Conflicts:
	_defaults.scss
	objects/_sprite.scss
Merge branch 'feature/submodule' of github.com:csswizardry/inuit.css into feature/submodule