* src/main.c: Display window before loading command line specified projects.

	* gladeui/glade-project.[ch]: Added dialog that pops up when about to load
	  a large project with glade_project_push_project() to push the progress and
	  glade_project_load_cancelled() to check and abort while loading the project.

	* gladeui/glade-widget.c, gladeui/glade-widget-adaptor.c: Push progress and
	  abort loading when project indicates the user cancelled the load.