CLOUDSTACK-6647: appending instance name with custom supplied info that contains - character can break vmsync.
CLOUDSTACK-6607: Correct the result of VpcNetworkUsage

Blank or not shouldn't be used to indicate command is failure or not.
CLOUDSTACK-5501: Allow one vpn customer gateway with multiple connections

This restriction was purposely avoid confusion of VPN setup, but later found too
strictly and cause troubles for deployment. Removed after testing one customer
gateway with multiple connections.