formaction attribute support

[kakone]

Hello,

I reopen a new issue because the problem is still there. The problem is very simple: the formaction attribute on button or input is not taken into account.

This is a sample that reproduces the problem : http://plnkr.co/edit/lc82fluYOGguSHIeKJs2?p=preview
When you click on the "Submit to another page" button, the formaction value ("another_action.html") should be called. It's not the case.

The PR #36 corrects this.

[mkArtakMSFT]

Thanks @kakone. Closing this one in favor of the older issue, which I've just reopened: #40