Resolve "MODIF: make a MyAxes_factory"
Closes #91
On the way to full factories
need cleaning:
D_HIERARCHY should become D_CONTEXT and should take only low case parameter. need clean unnecessary imports in /init.py The AxesClassFactory may be renamed The AxesClassFactory may not be the most elegant... since modifications are done for all subclasses too, but actually need to be done only on base class. may need some rethought.