Add visibility icons in publisher dropdown aspect

This PR add the globe or the lock icon to the publisher aspect dropdown to make more clear that the post is public or limited. Fix https://github.com/diaspora/diaspora/issues/4974
This is the line which makes the test to fail. ```$('#visibility-icon').hasClass('lock');``` returns true if you try it in the JS console of Firefox, but if you put a breakpoint on that line and try it during the Jasmine test, it returns false. Does that mean that the class has not been added yet when the script is run? How should I solve that?