function test_props_all( prop, callback ) {
      
        var uc_prop = prop.charAt(0).toUpperCase() + prop.substr(1),
            props   = (prop + ' ' + domPrefixes.join(uc_prop + ' ') + uc_prop).split(' ');

        return !!test_props( props, callback );
    }
test_props_all tests a list of DOM properties we want to check against.
  We specify literally ALL possible (known and/or likely) properties on 
  the element including the non-vendor prefixed one, for forward-
  compatibility.