[PATCH 1 of 3 stable] util.url: add an 'islocal' method

[Siddharth Agarwal]

On 02/03/2014 03:12 PM, Siddharth Agarwal wrote:
> # HG changeset patch
> # User Siddharth Agarwal <sid0 at fb.com>
> # Date 1391467661 28800
> #      Mon Feb 03 14:47:41 2014 -0800
> # Branch stable
> # Node ID 8ab8a85a22c2f5a0e23e86f2041ef7d348fab857
> # Parent  9139dedeffa6d54367fcf410d583d401e8fd1318
> util.url: add an 'islocal' method
>
> This returns True if the URL represents a path that can be opened locally,
> without needing to go through the entire URL open mechanism.

Of course, this now raises the question whether url.open should do this 
detection. Is it ever desirable for url.open to not use posixfile directly?