* generator/ObjectGen.cs : don't gen a Signals hash per class.
* generator/Signal.cs : gen checks for [ConnectBefore].
* generator/SignalHandler.cs : add connect_flags param to ctor.
* glib/ConnectBeforeAttribute.cs : new attr
* glib/Makefile.am : add new file
* glib/Object.cs : add before/after hashes and EventLists
* gnome/CanvasProxy.cs : use AfterSignals and AfterHandlers.
svn path=/trunk/gtk-sharp/; revision=24157
