Remove MicroData implementation

LayoutTests/fast/dom/MicroData/itemref-for-an-element-must-be-correct-expected.txt

-This test that the itemRef should be correct for an element that has itemRef attribute.
-
-Created element of type: div
-Set attribute: itemref, value: foo bar FOO FOo
-PASS element.itemRef.length == 4 is true
-PASS element.itemRef.toString() == 'foo bar FOO FOo' is true
-PASS element.itemRef.item(0) == 'foo' is true
-PASS element.itemRef.item(1) == 'bar' is true
-PASS element.itemRef[0] == 'foo' is true
-PASS element.itemRef[1] == 'bar' is true
-PASS element.itemRef.contains('bar') is true
-PASS element.itemRef.contains('foo') is true
-
-itemRef should return case-sensitive strings.
-PASS element.itemRef.item(2) == 'FOO' is true
-PASS element.itemRef[2] == 'FOO' is true
-PASS element.itemRef.item(3) == 'FOo' is true
-PASS element.itemRef[3] == 'FOo' is true
-
-itemRef should not contain an undefined token.
-PASS element.itemRef.contains('test') is false
-
-itemRef.length should be 0 if element has not tokens.
-Created element of type: div
-Set attribute: itemRef, value: 
-PASS element1.itemRef.length == 0 is true
-PASS successfullyParsed is true
-
-TEST COMPLETE
-