Support for InvokeAsync

[analogrelay]

We only support SendAsync-style invocation in the Java Client right now. We need support for waiting for the server to finish the invocation.

[BrennanConroy]

Small issue with invoke, Java generics are really great so we need to pass the class type of the return value into the function call.

public <T> T invoke(String target, Class<T> returnType, Object... args);
Are we ok with that signature, or is there a different way we can do this. @anurse @mikaelm12

[analogrelay]

Sounds like this is the way we have to do it, so let's do it. I wonder if we should put the return type first?

.invoke(String.class, "GetProductName", 123, 456);

vs

.invoke("GetProductName", String.class, 123, 456);

I like the first one (return type first) because a) it looks closer to the C# and b) it keeps the method name and args together.

[BrennanConroy]

4b37869