README

* Keep your modifications to the necessary minimum: A patch
  containing several unrelated changes or arbitrary reformats will be
  returned with a request to re-formatting / split it.

* If you modify existing code, make sure that your new code does not
  add to the memory footprint of the code ;-) Small is beautiful!
  When adding new features, these should compile conditionally only
  (using #ifdef), and the resulting code with the new feature
  disabled must not need more memory than the old code without your
  modification.