tests(protractor): advanced features for ElementArrayFinder

User in StackOverflow reports `$$('i.icon-trash').click();` isn't [working for him](http://stackoverflow.com/questions/25896061/protractor-how-to-click-all-delete-buttons-in-a-page-object/25985521?noredirect=1#comment40757134_25985521)

Works for me and tried to find a clear test case to prove him wrong but could only found `selected by filter` examples so adding this one.