Patch reported by Anthony Mallet.

This solution worked only for win32 systems, and
created link errors for unix systems...

This reverts commit e7e487ebdf9c550742d4c9525bbb151e25437393.

    Call to g_caster function have been replaced by call to
    SignalCaster::getInstance.

    g_pool and g_factory global variables have been replaced by static methods
    getInstance in each class.
    getInstance returns a pointer to the unique instance of the class and
    creates it if needed.

Code cleaning after rewriting (marginal) of sig-cast. Introduction of a specific tracer behaviour for matrix and vector.

      Remove pool::getSignal().

       This reverts commit 8fca0b1a.
       Move python interpreter in dynamic-graph-python.

       This reverts commit 0b9f9528.
       Move python interpreter in dynamic-graph-python.

     * src/CMakeLists.txt,
     * tools/CMakeLists.txt.