* Now headers only include headers they use (at least std headers).
* Remove CFU_DEBUG stuff since NDEBUG automatically controls assert()
* Make use of CFU_BEGIN_DECLS and CFU_END_DECLS macros from cfu.h.
The '%lu' isn't stricly right either, but now this commit can be
referred to find locations to fix with the more correct '%zu' or
'PRIuMAX' or whatever is the right thing to use.
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.