This is required in order to make import of module dl succeed.

	  Executable dg-python emulates a minimal python interpreter.
	  The interpreter is able to
	    - execute single statements: (import, print,...),
	    - evaluate expressions.
	  Expressions and statements are separated by semi-colons. Several
	  statements and/or evaluations between two semi-colons yield an
	  undefined behavior.

    * src/CMakeLists.txt,
    * src/dynamic-graph-py.cc.

     * src/CMakeLists.txt,
     * src/dynamic-graph-py.cc,
     * src/factory-py.cc: new.

	  * src/CMakeLists.txt,
	  * src/dynamic-graph-py.cc,
	  * src/dynamic_graph/__init__.py,
	  * src/dynamic_graph/entity.py: new,
	  * src/dynamic_graph/signal_base.py: new,
	  * src/entity-py.cc: new,
	  * src/signal-base-py.cc: new.

    * src/CMakeLists.txt.