Use LinkedHashSet to preserve the order of the elements. Always render "fa fa-fw" in front of the custom FontAwesome classes
ISIS-537 Remove 'form-control' for the BooleanPanel's checkbox to avoid flickering - initially it appears as a larger box then it is resized and moved to the left.

Now it appears as a normal checkbox and then it is styled. There is again flickering but not so intrusive. Select2 also behaves this way.
Merge remote-tracking branch 'martin-g/build-with-java8'
Merge remote-tracking branch 'martin-g/boolean-panel-checkbox-flickering'