SOVERSION defaults to 1.0. SHARED_LIBS, however, could be changed
at any point.  Ensure they are on sync in case INSTSONAME is used
by a third party.

Index: configure.ac
--- configure.ac.orig
+++ configure.ac
@@ -479,7 +479,7 @@ esac
 
 if test $define_xopen_source = yes
 then
-  AC_DEFINE(_XOPEN_SOURCE, 600, 
+  AC_DEFINE(_XOPEN_SOURCE, 700, 
             Define to the level of X/Open that your system supports)
 
   # On Tru64 Unix 4.0F, defining _XOPEN_SOURCE also requires
@@ -489,7 +489,7 @@ then
   AC_DEFINE(_XOPEN_SOURCE_EXTENDED, 1,
    	    Define to activate Unix95-and-earlier features)
 
-  AC_DEFINE(_POSIX_C_SOURCE, 200112L, Define to activate features from IEEE Stds 1003.1-2001)
+  AC_DEFINE(_POSIX_C_SOURCE, 200809L, Define to activate features from IEEE Stds 1003.1-2001)
   
 fi
 
@@ -930,6 +930,9 @@ if test $enable_shared = "yes"; then
 	  case $ac_sys_system in
 	      FreeBSD*)
 		SOVERSION=`echo $SOVERSION|cut -d "." -f 1`
+		;;
+	      OpenBSD*)
+		SOVERSION=${LIBpython2.7_VERSION}
 		;;
 	  esac
 	  INSTSONAME="$LDLIBRARY".$SOVERSION