Add wildcard Nginx rules to load default VVV domains via xip.io

local.wordpress.*.xip.io
local.wordpress-trunk.*.xip.io
src.wordpress-develop.*.xip.io
build.wordpress-develop.*.xip.io
where * represents an IP address

The goal of these rules is to allow other devices on your network to
load these websites using URLs like the following
local.wordpress.192.168.1.10.xip.io
local.wordpress.10.0.1.20.xip.io

See #263
Merge pull request #449 from salcode/nginx-xip-io-rules

Add wildcard Nginx rules to load default VVV domains via xip.io