CLOUDSTACK-2285:[GSLB] addNetscalerLoadBalancer with GSLB functionality
shouldn't be exposed in basic zone

reverting the original fix for this bug. When you add network service
provider instance into a physical network in a basic zone, its not
necessary that a network has been provisioned into zone. So its no
straight-forward to know if the basic zone network has EIP/ELB services enabled.
CLOUDSTACK-2192: [EIP/Optonal PublicIP] listNetworkOfferings is not
returning info about the capability "AssociatePublicIP"

added eip and associateEip capability details to the StaticNat service
response
CLOUDSTACK-2332:[GSLB] deleteAccount is not cleaning the gslb rules
created by the account

revoking GSLB rules of account on delete