API and non-API functions and giving _sk_ prefix for all non-API
functions. Old names will be available by _SKEY_INTERNAL define
it allows not change anything in keyinit & key, only -D_SKEY_INTERNAL required.
Staticise some things.
specified in the top level Makefiles.
Previously I missed dozens of Makefiles that skip the install after
using `cmp -s' to decide that the install isn't necessary.
2 Added optional excessive login logging.
3) Added login acces control on a per host/tty base.
4) See skey(1) for skey descriptions and src/usr.bin/login/README
for the logging and access control features.
-Guido