o stay_setuid - sudo will remain setuid if system has saved uids or setreuid(2)
o env_reset - reset the environment to a sane default
o env_keep - preserve environment variables that would otherwise be cleared
No longer use getenv/putenv/setenv functions--do environment munging by hand.
Potentially dangerous environment variables can be cleared only if they
contain '/' pr '%' characters to protect buggy programs.
Moved environment routines into env.c (new file)
Michael D. Marchionna.
configure now does substitution on the man pages, allowing us to
fix up the paths and set the section correctly. Based on an idea
from Michael D. Marchionna.
