Milter-greylist

> NB: we droped select(2) for poll(2) in MX sync. Please raise your voice if it
> causes regressions.
> 

I got:

gcc -g -O2 -Wall -I/usr/local/src/sendmail/libmilter/include -I/usr/local/src/spf/libspf2/include -DUSE_SPAMD -DHAVE_DATA_CALLBACK -DCONFFILE=\"/etc/mail/greylist.conf\" -DDUMPFILE=\"/var/milter-greylist/greylist.db\" -D_BSD_SOURCE -I. -I.    -c -o sync.o sync.c
sync.c: In function 'sync_waitdata':
sync.c:1325: error: 'INFTIM' undeclared (first use in this function)
sync.c:1325: error: (Each undeclared identifier is reported only once
sync.c:1325: error: for each function it appears in.)
make: *** [sync.o] Error 1

From the man page of poll on Linux:

NOTES
       Some implementations define the non-standard constant INFTIM with the value -1 for use as a timeout.  This con-
       stant is not provided in glibc.