Andreas Rottmann's patch to support g-wrap 1.9.

[Derek Atkins]

Log Message:
-----------
Andreas Rottmann's patch to support g-wrap 1.9.

	* engine/gw-engine-spec.scm:
	* gnome-search/dialog-search.h:
	* report/report-gnome/dialog-column-view.h:
	  Andreas Rottmann's patch to support g-wrap 1.9.
	  - don't wrap non-existent objects
	  - protect headers from multiple inclusion
	  - include gtk.h header when we use gtk objects.

Modified Files:
--------------
    gnucash/src/engine:
        gw-engine-spec.scm
    gnucash/src/gnome-search:
        dialog-search.h
    gnucash/src/report/report-gnome:
        dialog-column-view.h