Multiple buttons

d.o issue: https://www.drupal.org/node/2273361

Note: This is just the first step in order to support different types of entities for selection. Read my last comment (short essay: https://www.drupal.org/node/2273361#comment-8999597) on the issue for more details.
Yes, that's on my list of todo's. Since I'm still not sure how to allow user to config icons, I plan to do this as follow-up. I wanted to get a basic structure in first.