Auto-detect hstrerror. Raise socket.herror in PyH_Error. Register the three
exception classes in the module dictionary.
diff --git a/configure.in b/configure.in
index 2d163d3..5ec8b44 100644
--- a/configure.in
+++ b/configure.in
@@ -1178,7 +1178,7 @@
 AC_CHECK_FUNCS(alarm chown clock confstr ctermid ctermid_r execv \
  flock fork fsync fdatasync fpathconf ftime ftruncate \
  getgroups getlogin getpeername getpid getpwent getwd \
- inet_pton kill link lstat mkfifo mktime mremap \
+ hstrerror inet_pton kill link lstat mkfifo mktime mremap \
  nice pathconf pause plock poll pthread_init \
  putenv readlink \
  select setegid seteuid setgid \