bridge: update documentation references

Update the references to bridge utilities and web pages
to current locations
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/bridge.txt

 In order to use the Ethernet bridging functionality, you'll need the
-userspace tools. These programs and documentation are available
-at http://www.linuxfoundation.org/en/Net:Bridge.  The download page is
-http://prdownloads.sourceforge.net/bridge.
+userspace tools.
+
+Documentation for Linux bridging is on:
+   http://www.linuxfoundation.org/collaborate/workgroups/networking/bridge
+
+The bridge-utilities are maintained at:
+   git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/bridge-utils.git
+
+Additionally, the iproute2 utilities can be used to configure
+bridge devices.
 
 If you still have questions, don't hesitate to post to the mailing list 
 (more info https://lists.linux-foundation.org/mailman/listinfo/bridge).