Fixed administration. When leave the boards module, GCompris was quitting. This bug has been
	  introduced in a fix the 2006-07-10.
	  Now leaving GCompris in administration mode, there is no more segfaults.

	* boards/oscar_and_friends/scene1_0.png: improved by Josef Vybiral
	* configure.in: added support for gnet (disabled by default)
	* src/boards/python/admin/module_boards.py: fixed management of the module state. no more double stop modules.
	* src/boards/python/admin/module_users.py: -
	* src/boards/python/administration.py: -
	* src/boards/python/oscar_and_friends.py: changed text coordinate and colors
	* src/gcompris/Makefile.am: added gc_net.*
	* src/gcompris/gc_net.c: empty now, will hold the network code
	* src/gcompris/gc_net.h: -
	* src/gcompris/board.c: (board_pause), (board_stop),
	(get_board_playing):
	* src/gcompris/board.h: cleanup, removed pause board state saving. now board_pause takes an argument, no more a toggle.
	* src/gcompris/board_config.c: (gcompris_combo_box_changed),
	(my_strcmp): added several static. code cleanup.
	* src/gcompris/gameutil.c: (gcompris_load_pixmap),
	(gcompris_dialog), (item_event_ok): prepared net code.
	* src/gcompris/gcompris.c: (gcompris_end_board), (cleanup),
	(gcompris_exit), (quit_cb), (gcompris_init): fixed quit sequence. now a real exit is done after gtk_main_quit
	* src/gcompris/gcompris.h: added gc_net
	* src/gcompris/properties.c: (gcompris_properties_new): added server option
	* src/gcompris/properties.h: -
	* src/gcompris/sdlplayer.c: (sdlplayer_init), (sdlplayer_quit),
	(sdlplayer_bg): replaced printf by g_warning
	* src/gcompris/skin.c: (gcompris_image_to_skin): no more return an empty skin but the default one anyway. It will fail later on
	  anyway if the image is not available.