* DNR.c: Add Apple MacTCP source file for domain name resolution.

* DNR.c:  Add Apple MacTCP source file for domain name resolution.
* macsock.c:  Add fake socket support routines for MacTCP.
* Makefile.in (OBJS, SRCS):  Add DNR and macsock.
* ccdefname.c:  On Mac, default cred cache is "STDIO:krb5cc" for now.
FIXME, this needs to find the Preferences folder and use that.
FIXME, shouldn't be conditioned on HAVE_MACSOCK_H.
* gmt_mktime.c:  Use HAVE_SYS_TYPES_H.
* krbfileio.c:  Remove <sys/types.h>.
* localaddr.c, sendto_kdc.c:  Convert to more generic socket
support.  Use closesocket instead of close, SOCKET_ERRNO rather
than errno, SOCKET rather than int, etc.
* localaddr.c:  Use getmyipaddr() from macsock.c, if on Mac.
Add FIXME for multiple local addresses.
* lock_file.c:  Provide a dummy version for MacOS.
* read_pwd.c (ECHO_PASSWORD):  Add #ifdef's to avoid all the ioctls
and other stuff that turn off echoing.  This is useful for debugging
on MacOS.  FIXME:  ECHO_PASSWORD needs to be added to configure.in.
* ustime.c:  Bring in Mac-specific time-and-timezone code.  It
probably isn't hooked up correctly, yet.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@5299 dc483132-0cff-0310-8789-dd5450dbe970