Replace => syntax with =

[davidanthoff]

This implements #12. The old syntax still works but shows a deprecation warning.

[mdcfrancis]

I'm seeing a merge conflict here - is there anything wrong with supporting both the pair interface and the named arg interface ?

[davidanthoff]

If we implement #13, the pair syntax would conflict because @NT(a=>3) should then actually construct a named tuple with one automatically named member of type Pair. We could also implement #13 without support for automatically named members, in wich case I think we could keep the pair syntax around.

Generally it seemed cleaner to me to just have one syntax, and it requires less tests etc. On the other hand, if there is a lot of code out there that uses the pair syntax, it might not be worth breaking... I don't feel strongly about this at all :)

I'll resolve the merge conflict as soon as I have better internet (on a plane right now).

[davidanthoff]

Alright, I rebased.

[davidanthoff]

@mdcfrancis and @JeffBezanson Bump, could we merge this, possibly before we merge #18?

If you don't want the deprecation warning, I'll just take that out for now.

[JeffBezanson]

Yes, I'm in favor.

[mdcfrancis]

Thanks