Add support for using Windows named pipes

[HCanber]

Background

One very common way of hosting node applications on Windows is to host them in IIS using iisnode.

iisnode provides the available port as a Windows named pipe and not as a port number in the environment variable port. Node can open named pipes, however the parse_address() function in utils.js does not allow them, so Sinopia cannot be hosted in iisnode on Windows.

This PR fixes that.

What's changed

This PR does not change any of the existing behavior, if a port number or url has been specified it's still used.

However, if it's not one of those a check is made to see if the incoming port looks like a Windows named pipe, and in that case uses that.
This PR also fixes logging so correct protocol is logged, and add tests for Windows named pipes.

How to host Sinopia in iisnode

With this PR Sinopia can be used in iisnode by creating a project, npm install --save sinopia2 and then create index.js:

process.argv.push('--listen', process.env.PORT || '4873')
require('./node_modules/sinopia2/lib/cli')

Configure iisnode to use index.js as start file.

Named pipes

A named pipe in Windows has the format:
\\.\pipe\PipeName

• The period specifies the local computer
• The pipe name string specified by PipeName can include any character
  other than a backslash, including numbers and special characters.

From: https://msdn.microsoft.com/en-us/library/windows/desktop/aa365783(v=vs.85).aspx

[dgaya]

Looks good. Waiting for +1.