Add extra tests for spec change relating to RadioNodeList

http://html5.org/tools/web-apps-tracker?from=8743&to=8744
Cleanup the close tests a bit.
Add some tolerance to lastModified test
Give the close tests useful names.
Merge pull request #1240 from Ms2ger/close

Cleanup WebSocket.close() tests; r=zcorpan
Merge pull request #1236 from Manishearth/patch-2

Add some tolerance to lastModified test
Merge pull request #1233 from djc/radionodelist-value-on

Add extra tests for spec change relating to RadioNodeList