Rename script

[Jimvy]

As suggested in #835

Currently, this script supports the following:

• Change of quadri
• Change of course code (either the option like SINF or the number like 1252)
• Change of course name (like coo, os...)
• Change of course title

In order to make it work and keep the other scripts functional, I had to change a bit the config.yml, so that it stays with the "names" at the end of file even after PyYAML's reordering.

Current limitations:

• Has some difficulties when different courses share the same course name, as it considers that only one course has a given course name (in database parlance, the course name is a primary key). This breaks for crypto q7/q8, and also for meca, elec, math etc courses.
• For now, exams and tests have their \hypertitle also updated. Maybe we should keep the old quadri/title/course code in old exams. Open to discussion (it's a 3 lines fix in the code).
• It leaves the working tree without any addition to Git; maybe we can integrate Git with it, so that it git adds the files.
• On Windows, one has to call it using explicitly python; it's more a feature than a bug however...

Bad things:

• It's extremely over-engineered probably, but at least it supports nearly all corner cases that I can think of.
• Python 3 + Windows + Unicode + PyYAML = nuclear explosion of bugs and strange issues.

[Peiffap]

Shouldn't limitations be considered "bad things" as well 😉? I'll look at this when I have some time.