Add automake support for --enable-gcc-hidden-visibility.

configure.in.in

@@ -1,4 +1,6 @@
 #MIN_CONFIG(3.2.0)
+KDE_ENABLE_HIDDEN_VISIBILITY
+KDE_INIT_DOXYGEN([KDE Utils API Reference], [Version $VERSION])
 
 AM_INIT_AUTOMAKE(autostart, 0.1)
 AC_C_BIGENDIAN