Abstraction for the State classes
This PR represents the first action regarding the creation of abstract classes for the core classes (reported here #74 (closed)). Here I have been focused on State classes, these are the tasks:
- Created StateAbstract class and used for all State implementations (i.e. StateVector, StateNumDiff, StatePinocchio and StateUnicycle)
- Added verbose documentation to the StateAbstract
- Improved the documentation for the StateXXX classes.
- Clean up code of State classes.
Edited by Carlos Mastalli