round has been tested on Solaris/x86 and Linux hosts.
* Add host tools cap_mkdb, ctags, m4, uudecode.
* Protect __RCSID() and __COPYRIGHT() better.
* Reduce the number of places that need to include "config.h", to keep
sources closer to their "vanilla" versions.
* Add more compat #defines and autoconf-checked functions.
This means that <ufs/*/*.h> come from ../../sys/ufs, but other
<sys/*> header files still come from the host system's /usr/include.
This slightly ugly hack to the Makefile means that makefs compiles on
-current and 1.5.x machines (and other systems), without requiring
major code rewrites in sys/ufs/ffs to allow sharing and without
requiring duplication of sys/ufs/ffs* under usr.sbin/makefs.
