Missing defines for LLONG_MAX and LLONG_MIN

Some systems may not yet have defined LLONG_MAX and LLONG_MIN in
limits.h, in particular older GLIBC installs are affected.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/strtonum.c

@@ -26,6 +26,15 @@
 #define	TOOSMALL	2
 #define	TOOLARGE	3
 
+#ifndef LLONG_MAX
+# define LLONG_MAX	0x7fffffffffffffffLL
+#endif
+
+#ifndef LLONG_MIN
+# define LLONG_MIN	(-0x7fffffffffffffffLL - 1)
+#endif
+
+
 long long
 strtonum(const char *numstr, long long minval, long long maxval,
     const char **errstrp)