TODO before 1.0
===============

- Check portability:
        - sqrt(-1), x/0.0 etc. -->  crash, or NaN/Inf?
        - Are functions like log2 and cbrt available everywhere, etc.?

- Take a look at the localisation/translation stuff.


Beyond 1.0:
===========

- Better precision (e.g. using mpfr)


- More functions? (Hyperbolics? Gamma?)
        - easy to add, as long as they are implemented in the C math
          library.
        - Add support for multi argument functions?