support for Hurd (is it even used?)

libetpan-config.h.in

@@ -15,6 +15,9 @@
 #ifdef HAVE_LIMITS_H
 @include <limits.h>
 #endif
+@ifndef PATH_MAX
+@define PATH_MAX 4096
+@endif
 #ifdef HAVE_SYS_PARAM_H
 /* support for ARM platforms with a 2.95.3 arm-gcc suite */
 @include <sys/param.h>

tests/option-parser.c

@@ -6,12 +6,15 @@
 #	include <getopt.h>
 #endif
 
-#ifdef HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
 
 #include <libetpan/libetpan.h>