MAXHOSTNAMELEN and the MIN/MAX macros. We now use PATH_MAX and
HOST_NAME_MAX throughout without falling back on MAXPATHLEN or
MAXHOSTNAMELEN and define our own MIN/MAX macros as needed.
Add sudo_printf function pointer that is initialized to _sudo_printf()
instead of requiring a sudo_conv function pointer everywhere. The
plugin will reset sudo_printf to point to the version passed in via
the plugin open function. Now plugin_error.c can just call sudo_printf
in all cases. The sudoers binaries no longer need their own version
of sudo_printf.
