Remove protocall/runtime/service.cpp

We can just use the header.
Add receive(bool nonBlocking) method to vtkCommunicatorChannel

Declaration that delegates to superclass.
Remove runtime library

Rather than build runtime library, install runtime source
and add it to the common source provided to the user. This
is required as the message.pb.h generate at ProtoCall build
time will be different to the one generated when the user
compiles their .proto files (we are using protobuf extensions).
Update example to build runtime library