Cannot use IPV6 in CONSUL_HTTP_ADDR override

[digidenz]

This is due to the way it splits the value using ":" as the delimiter to extra the IP address and port number for IPV4 in Client.cs. This however doesn't work for IPV6.

[alexbfreeman]

Also doesn't work if you use an uri, like http://...

[thiagoloureiro]

@Trillian42
#130 to fix this