Convert INST_IO links to regular PV_LINK types, for VDCT support.

Added new PN_LINK type in link.h, make dbStaticLib display it.
Made all device support extended so links can be changed at runtime.
Modified startup so add_record() always called before regular link processing.
Incomplete, stilll need to add MS/MSS/MSI support, currently disabled.

src/ioc/dbStatic/dbStaticLib.c

@@ -59,6 +59,7 @@ epicsShareDef maplinkType pamaplinkType[LINK_NTYPES] = {
 	{"GPIB_IO",GPIB_IO},
 	{"BITBUS_IO",BITBUS_IO},
 	{"MACRO_LINK",MACRO_LINK},
+        {"PN_LINK",PN_LINK},
 	{"DB_LINK",DB_LINK},
 	{"CA_LINK",CA_LINK},
 	{"INST_IO",INST_IO},
@@ -291,7 +292,8 @@ static long setLinkType(DBENTRY *pdbentry)
     }
 
     type = plink->type;
-    if ((type == CONSTANT || type == PV_LINK || type == DB_LINK || type == CA_LINK) &&
+    if ((type == CONSTANT || type == PV_LINK ||
+         type == PN_LINK || type == DB_LINK || type == CA_LINK) &&
 	(link_type == CONSTANT || link_type == PV_LINK)) goto done;
 
     dbFreeLinkContents(plink);
@@ -2015,6 +2017,12 @@ char * epicsShareAPI dbGetString(DBENTRY *pdbentry)
 		    strcpy(message,"");
 		}
 		break;
+            case PN_LINK:
+                if(plink->value.pv_link.pvname)
+                    strcpy(message,plink->value.pv_link.pvname);
+                else
+                    strcpy(message,"");
+                break;
 	    case PV_LINK:
 	    case CA_LINK:
 	    case DB_LINK: {
@@ -3706,6 +3714,7 @@ int  epicsShareAPI dbGetLinkType(DBENTRY *pdbentry)
 	case CONSTANT:
 	    return(DCT_LINK_CONSTANT);
 	case PV_LINK:
+        case PN_LINK:
 	case DB_LINK:
 	case CA_LINK:
 	    return(DCT_LINK_PV);

src/ioc/dbStatic/link.h

@@ -35,13 +35,15 @@ extern "C" {
 #define GPIB_IO		5
 #define BITBUS_IO	6
 #define MACRO_LINK	7
+
+#define PN_LINK         9
 #define DB_LINK		10
 #define CA_LINK		11
 #define INST_IO		12		/* instrument */
 #define	BBGPIB_IO	13		/* bitbus -> gpib */
 #define RF_IO		14
 #define VXI_IO		15
-#define LINK_NTYPES 14
+#define LINK_NTYPES 15
 typedef struct maplinkType{
 	char	*strvalue;
 	int	value;