Add a new role 'gw' for 'gateway' interfaces

sql/database-create.sql

@@ -456,7 +456,7 @@ CREATE TABLE interfaces (
   mask varchar(15) default NULL,
   interface_type varchar(30) default NULL,
   iface text NOT NULL,
-  role enum('ctrl','expt','jail','fake','other') NOT NULL default 'other',
+  role enum('ctrl','expt','jail','fake','other','gw') default NULL,
   current_speed enum('100','10','1000') NOT NULL default '100',
   duplex enum('full','half') NOT NULL default 'full',
   PRIMARY KEY  (node_id,card,port),

sql/database-migrate.txt

@@ -1002,3 +1002,8 @@ last_net_act,last_cpu_act,last_ext_act);
 1.190: Add an index...
 
        alter table testbed_stats add key (exptidx);
+
+1.191: Add a new role 'gw' for 'gateway' interfaces:
+
+       alter table interfaces modify role enum('ctrl','expt','jail','fake', \
+           'other','gw');