Some changes to ext2sim and extresist to support arbitrary device

types and substrate connections.  This is an intermediate step to
switching from a sim file format to an ext file format for input,
but resolves the worst issues of having the sim file not recognize
the devices or the substrate nodes.  Implemented by using the sim
subcircuit format introduced in IRSIM with the "user subcircuit"
package.  Implementation unfinished (work in progress).

resis/resis.h

@@ -293,6 +293,7 @@ typedef struct rdev
      struct ressimnode	*gate;		/* Terminals of transistor.	  */
      struct ressimnode	*source;
      struct ressimnode	*drain;
+     struct ressimnode	*subs;		/* Used with subcircuit type only  */
      Point		location;	/* Location of lower left point of */
      					/* device.			   */
      float		resistance;     /* "Resistance" of device.	   */
@@ -519,6 +520,7 @@ typedef struct capval
 #define		GATE 1
 #define		SOURCE 2
 #define		DRAIN 3
+#define		SUBS 4
 
 #define 	DRIVEONLY	0x00001000
 #define 	ORIGIN 		0x00000008
@@ -610,6 +612,7 @@ extern int	      		ResSimCapacitor();
 extern int	      		ResSimResistor();
 extern int	      		ResSimAttribute();
 extern int			ResSimMerge();
+extern int			ResSimSubckt();
 extern int 			dbSrConnectStartFunc();
 extern int			ResEach(),ResAddPlumbing(),ResRemovePlumbing();
 extern float			ResCalculateChildCapacitance();