This is some code I had previously written, adapted to (mostly)
libcfu coding style. The API is very similar to that of the
existing (to be eventually removed) cfutime.
All of the files from the tarball downloaded from SourceForge are
being checked in so there's a record of the changes made compared
to it (since I can't find the libcfu source repository). The
generated files will be removed in the following commit.