New header containing GTK_DEBUG-style debugging support for GLib.

New header containing GTK_DEBUG-style debugging support for GLib.

	* glib/gdebug.h: New header containing GTK_DEBUG-style debugging
	support for GLib. Currently only the fatal_warnings debug option exists.

	* glib/gmessages.c (g_log_msg_prefix_init): New one-shot function
	for parsing G_MESSAGES_PREFIXED.
	(_g_debug_init): New one-shot function for parsing G_DEBUG.
	(g_log_write_prefix): Use g_log_msg_prefix_init().
	(g_messages_init): Use g_log_msg_prefix_init() and _g_debug_init().

	* glib/Makefile.am (libglib_1_3_la_SOURCES): Add gdebug.h.

	* glib/Makefile.am (IGNORE_HFILES): Add gdebug.h.

	* glib/running.sgml: Document the G_DEBUG environment variable.

	* glib/tmpl/threads.sgml: Replace g_thread_wait() by
	g_thread_join() in two places.