Release of version 1.2.0.

as it prevents to make a release

Pinocchio v2, fix #31

Conflicts:
	src/robots/robot-wrapper.cpp

Conflicts:
	bindings/python/contacts/contact-6d.hpp
	exercizes/ex_1.py
	exercizes/ex_2.py
	unittest/tsid-formulation.cpp

Introduce weight for motion task associated to RigidContact. Specify weight (for both motion task and force regularization task) when calling addRigidContact rather than when creating Contact object (to be coherent with weights of other Task's).

- Will set up preprocessor directives
- Then pkg-config check as usual will find include directories, libraries, etc.