Add support for virtual methods(vm) to the generator.
* parser/gapi2xml.pl: Generate a class_struct element with
all members of the class structure. Dump the first (instance)
parameter for signal and vm elements. Bump up parser version.
* generator/GObjectVM.cs: Added. Support for GObject virtual methods.
* generator/DefaultSignalHandler.cs: Signal specific part of vm
generation.
* generator/InterfaceVM.cs: New class for interface vms.
* generator/ObjectBase.cs: Parse the class struct.
svn path=/trunk/gtk-sharp/; revision=131604
