[ixpmanager] Patch Panels

[Barry O'Donovan]

Hi Mike,

Mike Hammett wrote:
> If there's rack\cabinet names alongside, then there probably won't be
> any confusion. I haven't had time to go any deeper with it yet today.

I've updated the help and documentation on this:

https://github.com/inex/ixp-manager-docs-md/commit/9472628d7e5f4a987d346b937b7d4388caa087b8

This includes adding a free text field in patch panels which is 
explained in the above.

> Also, you say to include both ports of a duplex port. If the panel
> itself doesn't provide any distinction between right and left strands,
> should I manually include that distinction? Ours just have letters for
> which column and numbers for which row, with a duplex connection
> occupying a single location.

Also added a new section on duplex ports to the documentation.

The tl;dr version is: IXP Manager offers flexibility, you need to make a 
decision on how best to use it to represent your own scenario.

  - Barry