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.
find_cycle was trying to find the longest cycle that a given node is part of,
which is a really, really hard problem (exponential?). instead, just detect
cycles. since the only difference is the (std error) output which is printed,
all works out OK.
