make bind ignore test methods

[iansmith]

Bind() should ignore attempts to bind a method that is not actually in the set of methods. It should probably issue a warning when it detects this situation.

Consider a .proto which says that foo() is a test method. That method may be implemented in some service (say bar) but not intended for use in prod. A nefarious person could try to bind foo() and then invoke it, which would be bad if the author of foo() expected it to only exist in a test situation.

This problem is really nasty because the decision of "is foo a test method()" is made at the time the code is generated and (intentionally) does not distinguish between test and normal methods so the tests can "work normally" without a bunch of shenanigans. The problem is that we would need to have a way to know when a bind is issued if it is legal or not, which at some level is going to need the .proto definition.