PIM-3202 pulish a little bit more the button style

Conflicts:
	src/Pim/Bundle/UIBundle/Resources/public/css/pim.less
Merge branch 'PIM-3202' of github.com:akeneo/pim-community-dev into PIM-3202

* 'PIM-3202' of github.com:akeneo/pim-community-dev:
  Improve indicator to allow adding additional classes when value is truthy or falsy

Conflicts:
	src/Pim/Bundle/UIBundle/Resources/public/css/pim.less