update grunt
Merge branch 'wip-0.6.0' of https://github.com/thierryc/wysihtml5-styled into wip-0.6.0

Conflicts:
	dist/wysihtml5-styled-bs2/js/wysihtml5-styled-bs2.min.js
	dist/wysihtml5-styled-bs3/js/wysihtml5-styled-bs3.min.js