Put MyModuleFoo class inMyModuleProcessing namespace

Move the MyModuleFoo class into new MyModuleProcessing namespace.
Update generation of manifest to take account of scope change.
Update mp_classloader app to load MyModuleFoo using the new namespace.

Clear that Poco's ClassLoader is happy to work with namespaced classes.
Put IProcessingModule in MicroPipeline namespace

Move IprocessingModule class inside new MicroPipeline namespace.

Update MyProcessingModule concrete classes and Manifest with new
scope.