Huuuuge update

This is the promised update, it is huge, all is basically reformatted, with a lot of additions.  This is still mostly (if not only) about the kinetics.  It is organized in three parts:
  - a physical part explaining the underlying physics and coded equations
  - a technical part about templates and optional libraries (entirely empty)
  - a tutorial part

I'll merge it somewhere in the week-end (if someone does not merge it before), just so you have some time to look at it and yell at me about things you don't like that I can change before merge.

All in all, it looks much better like this, with a special delightful meta-meta-macro in the preamble.