Deprecated _BSD_SOURCE warning

[jerome-jutteau]

Hi !

I was building libulz for the first time and I got a bunch of warning like this one:

cc -Os -std=c99 -I./include -c -o src/timelib/msleep.o src/timelib/msleep.c
In file included from /usr/include/time.h:25,
                 from src/timelib/../../include/timelib.h:11,
                 from src/timelib/msleep.c:1:
/usr/include/features.h:185:3: warning: #warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-Wcpp]
  185 | # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
      |   ^~~~~~~

I'm running Debian GNU/Linux bullseye/sid

What about replacing _BSD_SOURCE occurrences with _DEFAULT_SOURCE ?

Thanks for libulz !