COB-64: Allow LCS/MessageBus to be compiled without requiring python

LCS/MessageBus/CMakeLists.txt

 # $Id$
 
-lofar_package(MessageBus 1.0 DEPENDS Common pyparameterset)
+# Python can be explicitly disabled, if only the C++ libraries are needed
+if(USE_PYTHON)
+  lofar_package(MessageBus 1.0 DEPENDS Common pyparameterset)
+else(USE_PYTHON)
+  lofar_package(MessageBus 1.0 DEPENDS Common)
+endif(USE_PYTHON)
 
 include(LofarFindPackage)
 lofar_find_package(QPID)