Remove debug output

       * src/entity-py.cc.
Remove debug output

       * src/dynamic_graph/entity.py.
Allow SignalBase.value to take typed arguments

      * src/dynamic_graph/signal_base.py.
Re-inforce type checking.

     * src/dynamic-graph-py.cc,
     * src/dynamic_graph/__init__.py: plug now takes to signals as arguments
Add submodule cmake

    * .gitmodules,
    * cmake.
Add documentation generation using sphinx.

    * CMakeLists.txt,
    * doc/CMakeLists.txt,
    * src/dynamic_graph/signal_base.py.
Use submodule cmake to generate python documentation
Use autotools substitution rule.

    * cmake: synchronize,
    * doc/CMakeLists.txt: synchronize,
    * doc/sphinx/conf.py.in: new,
    * doc/sphinx/index.rst.in: new.
When building python Entity classes, populate methods with docstrings.

     * src/dynamic-graph-py.cc,
     * src/dynamic_graph/entity.py,
     * src/entity-py.cc.
Rename method in python module

       * src/dynamic-graph-py.cc: dynamic_graph.wrap.signalBaseGetTime ->
         signal_base_get_time.
Replace object member by obj in classes

	* src/dynamic_graph/__init__.py,
	* src/dynamic_graph/entity.py,
	* src/dynamic_graph/signal_base.py: object is a keyword in python.
Comply with jrl-mal syntax for vectors and matrices.

       * src/entity-py.cc.
Catch std::exception when executing command

      * src/entity-py.cc : for some reason, catching ExceptionAbstract is not
        sufficient.
Check that argument is string when string is expected in command.

      * src/entity-py.cc.
Set flags of dynamic loader so that symbols are global.

    * src/dynamic_graph/__init__.py.
Rewrite stringToTuple and stringToMatrix in a simpler way.

	* src/dynamic_graph/signal_base.py.
Fix a bug in conversion of tuple of tuple python object to matrix.

    * src/entity-py.cc.
Remove debug output.

       * src/entity-py.cc.
Catch std::exception instead of dynamicgraph::ExceptionFactory.

      * src/entity-py.cc.
Handle entity type as input to signal_base.value setter.

       * src/dynamic_graph/signal_base.py.