Update Select2
Allow passing args to select2 when creating the select field
Fix Select2 Button styles
Merge branch 'master' into select-2-options

Conflicts:
	css/dist/cmb.min.css
	css/src/generic.css
Merge pull request #232 from humanmade/select-2-options

Select 2 options
Merge branch 'master' into better-args-parsing
merge new select2 args