Test project builds on Mono, with types & completion for hub methods.

Use reference rather than reflection to invoke proxy (method was not available via reflection, but doesn't seem to
have binding context issue); avoid getting attribute definition as not implemented.
Clean up mostly unused code.

Noticed now there is not a locking of DLLs by the consuming project, but in the provider solution ReflectionProxy gets locked and need to restart VS to compile the TP.
WIP on complex arg types
Support for complex types!