group_info and use it to store both, along with a count for each.
Cache group info on a per-user basis using getgrouplist() to get
the groups. We no longer need special to special case the user or
list user for user_in_group() and thus no longer need to reset the
groups list when listing another user.
result of getgroups()) to names and store both the group names and
ids in the sudo_user struct. When matching groups in the sudoers
file, match based on the names in the groups list first and
only do a gid-based match when we absolutely have to. By matching
on the group name (as it is listed in sudoers) instead of id
(which we would have to resolve) we save a lot of group lookups
for sudoers files with a lot of groups in them.
Set adminstrative domain for the process when looking up user's
password or group info and when preparing for execve().
Include strings.h even if string.h exists since they may define
different things. Fixes warnings on AIX and others.
