Formatting the crocoddyl library, examples and apps (i.e. every single line of code)

We need to clean up the format inside our library. This task can be achieved by running a console command for each file inside crocoddyl. It will take few minutes of seconds.

I plan to use yapf for that (tool that @gsaurel is using). The only important thing is I need to agree a time for doing with you (@proyan and @nmansard). I propose to do it this Friday (March 1) at 16.00 CET. If agree with that, please be aware that it might create simple but annoyed conflicts with your current developments. If you want to avoid this please do a PR.

Please reply this before tomorrow. Feel free to suggest other dates.