add ChForceElementTire to swig to access subclasses from python
add ChForceElementTire to swig to access subclasses from python

rserban/chrono,dariomangoni/chrono,dariomangoni/chrono,rserban/chrono,projectchrono/chrono,dariomangoni/chrono,projectchrono/chrono,rserban/chrono,rserban/chrono,projectchrono/chrono,projectchrono/chrono,projectchrono/chrono,dariomangoni/chrono,rserban/chrono,dariomangoni/chrono,dariomangoni/chrono,rserban/chrono,projectchrono/chrono,rserban/chrono