only quote multi word values

fixes #8
fixes #9
fixes gruntjs/grunt-contrib-sass#150
fixes gruntjs/grunt-contrib-sass#151
fixes gruntjs/grunt-contrib-sass#152
2.0.2
Merge branch 'master' of https://github.com/sindresorhus/dargs into unquoted-quote

Conflicts:
	index.js
Fix for disabling quoting completely. Updated with latest changes.