Ignore right-click (and ctrl-click on OS X)
Ignore right-click (and ctrl-click on OS X)

Closes #63

hilotus/ember-sortable,raelbr/ember-sortable,dianafa/ember-sortable,raelbr/ember-sortable,jgwhite/ember-sortable,tim-evans/ember-sortable,hilotus/ember-sortable,dianafa/ember-sortable,tim-evans/ember-sortable,jgwhite/ember-sortable