Task #8571: fix CMake requirements on python messaging library

LCS/MessageBus/python/CMakeLists.txt

 # $Id: CMakeLists.txt 1584 2015-10-02 12:10:14Z loose $
 
-lofar_add_package(PyCommon common)
-lofar_add_package(PyMessaging messaging)
+add_subdirectory(common)
+add_subdirectory(messaging)

LCS/MessageBus/python/messaging/CMakeLists.txt

 # $Id$
 
-lofar_package(PyMessaging 1.0 DEPENDS PyCommon)
+#lofar_package(PyMessaging 1.0 DEPENDS PyCommon)
 
 include(PythonInstall)
 
@@ -9,6 +9,8 @@ set(_py_files
   exceptions.py
   messagebus.py
   messages.py
+  RPC.py
+  Service.py
 )
 
 python_install(${_py_files} DESTINATION messaging)

LCS/MessageBus/python/messaging/Service.py

@@ -42,6 +42,7 @@ class Service():
    def __enter__(self):
       self.Listen.open()
       self.Reply.open()
+      return self
 
    def __exit__(self, exc_type, exc_val, exc_tb):
       self.Listen.close()