Fix the file chooser on Windows. I can't make it misbehave or crash any

Fix the file chooser on Windows. I can't make it misbehave or crash any

2004-04-22  Tor Lillqvist  <tml@iki.fi>

	Fix the file chooser on Windows. I can't make it misbehave or
	crash any more now. But presumably there are still corner cases
	not handled. I haven't really checked behaviour of UNC paths, for
	instance.

	* gtk/gtkfilesystemwin32.c: Accept both backslash and slash in
	several places. Use G_IS_DIR_SEPARATOR macro (which could be added
	to GLib in 2.6).

	(gtk_file_system_win32_get_parent): Like the Unix version, assert
	filename is absolute, and avoid one unnecessary string allocation
	and freeing.

	(canonicalize_filename,gtk_file_system_win32_parse): Handle drive
	letters more correctly.

	(gtk_file_system_win32_render_icon): Assure correct syntax is used
	for root folder of a drive. (#137962, Morten Welinder)

	(filename_is_some_root): New function that accepts also root
	without any drive specified.

	(filename_is_drive_root): Rename from filename_is_root.

	* gtk/gtkfilechooserentry.c (completion_match_func): Casefold on
	Windows.