Wrangles the x-forwarded-for header value to get a best guess client ip address (left most non private ip)

When using X-Forwarded-For, the assumption is that the left most ip address is the originating client.

This is however often not the case when a corportate network or a public wifi is being used.

In this case the rule "Always use the leftmost non-private address" is the best practice.

Private ip ranges are:

• 10.0.0.0 – 10.255.255.255
• 172.16.0.0 – 172.31.255.255
• 192.168.0.0 – 192.168.255.255

This module inplements the points discussed here Wrangling the x forwarded for header by Rod Vagg

var getClientIp = require('x-forwarded-for-wrangler');

getClientIp(request.headers['x-forwarded-for'])