* 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.
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.
