Added support for VM extensions, static IPs, specification of arbitrary vm sizes and reserved IPs.

This PR contains changes for support for VM extensions, static IPs, specification of arbitrary vm sizes and reserved IPs.
Successful execution shows below output (see the last line), This should be sufficient to let know user that ip created.

$ node ./bin/azure network reserved-ip create  testresip01 "West US"
info:    Executing command network reserved-ip create
+ Creating reserved IP address
info:    network reserved-ip create command OK