CCAR: add a way to define component methods and attributes (not services)
for C++ and python components.
It is now possible to specify a class that is inherited by the generated
component class.
2 parameters (inheritedclass, compodefs) are added to the definition of C++
and python components.
- inheritedclass gives the name of the class to inherit
- compodefs gives the definition code to add in the beginning of the component
definition code (class definition, include or import)
