Metevolsim

- Improved model stability control. If 10 successive mutations lead to unstability, a critical error is raised.

- Improved SBML mutant model stability control.

- MetEvolSim does not use anymore species names which often collide. Only use species identifiers.
- A file "variables.txt" containing the list of variable names, identifiers and compartment is written each time a model is created.
- Improved CPS files edition and communication with CopasiSE.
- Some cosmetic corrections.

- Fully implemented the random sensitivity analysis and updated README accordingly,
- Updated copyright.

- Removed minor errors in README.md

- Python package case sensitivity debugging (2)