MFC r273127:

Make automountd(8) inform autofs(4) whether directory being handled can
have wildcards. This makes it possible for autofs(4) to avoid requesting
automountd(8) action on access to nonexistent nodes - unless wildcards
are actually used.

Note that this change breaks ABI for automountd(8).

MFC r278521:

Restore ABI compatibility, broken in r273127. Note that while this fixes
ABI with 10.1, it breaks ABI for 11-CURRENT, so rebuild of automountd(8)
is neccessary.

Sponsored by: The FreeBSD Foundation