Fix svg css binding

 :jack_o_lantern:  Using this PR, closes #1594.

@halidov, I trust you do not mind me closing your PR in favour of this one (it's just changing the target branch to my ko/fork). I can merge any other proposed changes you may have. Let me know if this resolves your issue.

Flagging for review and 3.3.0.
This needs to be `node.className['baseVal']`