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.
I don't see switch parameters are supported in 'site show' and 'storage account show'  commands.

Please see: https://github.com/Azure/azure-sdk-tools-xplat/blob/dev/lib/commands/asm/site._js#L467

$ node ./bin/azure site show -n anu
    error: unknown option `-n'
$ node ./bin/azure site show --name anu
    error: unknown option `--name'