AC_SUBST(USE_INCLUDED_SIGC)
AC_ARG_ENABLE(threads,
-[ --disable-threads disables support threading.],
-enable_threads=$enableval,enable_threads="yes")
+[ --enable-threads enable support threading.],
+enable_threads=$enableval,enable_threads="no")
AC_ARG_ENABLE(checks,
[ --disable-checks disables unnecessary tests needed for bug reports.],
enable_checks=$enableval,enable_checks="yes"