add "use_subscribe_notify" property in GtkUi config items to control whether...

add "use_subscribe_notify" property in GtkUi config items to control whether subscribes should be send and accepted.

git-svn-id: svn+ssh://svn.savannah.nongnu.org/linphone/trunk@741 3f6dc0c8-ddfe-455d-9043-3cd528dc4637