* generator/CallbackGen.cs : use new sig and isig classes.
* generator/Ctor.cs : use new sig, isig, and body classes.
* generator/ImportSignature.cs : isig code spun out from Parameters.
* generator/Method.cs : use new sig, isig, and body classes.
* generator/MethodBody.cs : spun Initialize, GetCallString,
Finish, and Exception throwing methods from Parameters.
* generator/Parameters.cs : Slayed the evilness that was CreateSignature.
It is now essentially a container for Parameter classes instead of a
tangled mess of code trying to do everything remotely related to
parameter lists. Also completely killed the VAType/IsVarArgs stuff,
as it can be done with the array and params attrs instead.
* generator/Property.cs : use new sig class.
* generator/Signature.cs : new method sig generator extracted from
Parameters class. add "params" keyword support for tagged parameters.
* gnome/Gnome.metadata : hide IconList.GetSearchPath (to be manual)
* gnome/gnome-api.xml : regen
* gtk/ListStore.custom : kill unneeded overload
* gtk/TreeStore.custom : kill unneeded overload
* gtk/Gtk.metadata : mark params/args on *store_newv
* gtk/gtk-api.xml : regenerated
svn path=/trunk/gtk-sharp/; revision=20755
