Add a convenience to help me build distfiles.

Originally committed to SVN as r1912.

configure.in

@@ -74,6 +74,13 @@ else
   AC_MSG_RESULT([no])
 fi
 
+AC_ARG_ENABLE(build-dist)
+if test "$enable_build_dist" = "yes"; then
+  SVN_VERSION=`svnversion .`
+  PACKAGE_STRING="${PACKAGE_STRING}-r$SVN_VERSION"
+  PACKAGE_VERSION="${PACKAGE_VERSION}-r$SVN_VERSION"
+  VERSION="${VERSION}-r$SVN_VERSION"
+fi
 
 
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