ISUP: Export {parse,encode}_isup_party()

Those functions are now used by the map_codec.erl
diff --git a/include/isup.hrl b/include/isup.hrl
index 55750ea..a1b5531 100644
--- a/include/isup.hrl
+++ b/include/isup.hrl
@@ -91,6 +91,7 @@
 -define(ISUP_PAR_USER_USER_IND,		2#00101010).	% User-to-user indicators
 -define(ISUP_PAR_USER_USER_INFO,	2#00100000).	% User-to-user information
 
+-define(ISUP_ADDR_NAT_SUBSCRIBER,	2#0000001).	% Subscriber number
 -define(ISUP_ADDR_NAT_NATIONAL,		2#0000011).	% National (significant) number
 -define(ISUP_ADDR_NAT_INTERNATIONAL,	2#0000100).	% International number