LookupLocator - deprecation of Discovery V1

[Peter Firmstone]

Presently, LookupLocator's method getRegistrar, discovers a lookup 
service, using Discovery V1 only.

ConstrainableLookupLocator overrides the getRegistrar method and can 
perform Discovery V1 or V2.

As a first step, in ensuring maximum compatibility, I'd like to propose 
changing LookupLocators implementation of getRegistrar to be identical 
to ConstrainableLookupLocator, but with InvocationConstraints.EMPTY, 
that is, without any constraints.

Secondly, I'd like to propose that Discovery V2 is used by default, and 
Discovery V1 can only be used by setting a system property, for 
migration purposes only.

Doing so will allow LookupLocator to function using either Discovery V1 
or V2.

This also reduces code duplication, presently there are two 
implementations of client side Discovery V1, this will reduce that to 
one implementation only.

Regards,

Peter.