Allow links and form submits to call `PushState.replace`

[jasononeil]

... not just PushState.push

It might look like:

 <a href='/home' rel="pushstate">New history item created</a>
 <a href='/blog' rel="pushstate-replace">NO new history item created</a>
 <a href='/home' class="pushstate">New history item created</a>
 <a href='/home' class="pushstate-replace">NO new history item created</a>

It would be implemented much the same way during PushState.init()

Ping @kevinresol

[jasononeil]

Is pushstate-replace the best name or is there something less.... verbose?

[kevinresol]

I would recommend a data-attribute. To me class is mostly used for css styling.

data-pushstate or data-pushstate="push" => push()
data-pushstate="replace" => replace()

but that would be a breaking change

[kevinresol]

or data-ps-push data-ps-replace?

[jasononeil]

I like the idea of using a data attribute. We can maintain the class/rel support for backwards compatibility but suggest using data-pushstate as the main option. I think I prefer that to data-ps also. It's more verbose but more obvious what it does...