Remove MicroData implementation

LayoutTests/fast/dom/MicroData/itemtype-add-remove-tokens-expected.txt

-This tests that itemType attribute must update correctly when token have been added or removed.
-
-Created element of type: div
-itemType.add must reflect correctly.
-PASS element.itemType.length == 2 is true
-PASS element.itemType.toString() == 'http://example.com/foo http://example.com/FOO' is true
-PASS element.itemType[0] is 'http://example.com/foo'
-PASS element.itemType[1] is 'http://example.com/FOO'
-PASS element.itemType.item(0) is 'http://example.com/foo'
-PASS element.itemType.item(1) is 'http://example.com/FOO'
-
-itemType.add must not make any changes if an existing token is added.
-PASS element.itemType.length == 2 is true
-PASS element.itemType.toString() == 'http://example.com/foo http://example.com/FOO' is true
-
-itemType.remove must reflect correctly.
-PASS element.itemType.length == 1 is true
-PASS element.itemType.contains('http://example.com/foo') is false
-PASS element.itemType.toString() == 'http://example.com/FOO' is true
-
-itemType.remove must not make any changes if remove is called for a token that doesn't exist.
-PASS element.itemType.length == 1 is true
-PASS element.itemType.contains('http://example.com/foo') is false
-PASS element.itemType.toString() == 'http://example.com/FOO' is true
-
-itemType.length must be 0 when all tokens are removed.
-PASS element.itemType.length == 0 is true
-PASS element.itemType.contains('http://example.com/foo') is false
-PASS element.itemType.contains('http://example.com/FOO') is false
-PASS successfullyParsed is true
-
-TEST COMPLETE
-