FRONTPANEL: General Enhancements

- added verification of the existence of simulator registers which they are referenced.
- sim_frontpanel API version checking to make sure that the invoking API and the simulator support the same capabilities.
- added the ability for a simulator to reference data in simh register data which is not in the set of registers defined in the default simh device (usually the CPU).
- added a simulator time reference relating to a set of register data which is provided.
- added example automatically creating a console terminal port from a simulator startup (front panel or not).

scp.c

@@ -225,6 +225,7 @@
 #include "sim_video.h"
 #endif
 #include "sim_sock.h"
+#include "sim_frontpanel.h"
 #include <signal.h>
 #include <ctype.h>
 #include <time.h>
@@ -4246,6 +4247,9 @@ if (flag) {
 #endif
 #if defined (SIM_ASYNCH_CLOCKS)
     fprintf (st, "\n\t\tAsynchronous Clock support");
+#endif
+#if defined (SIM_FRONTPANEL_VERSION)
+    fprintf (st, "\n\t\tFrontPanel API Version %d", SIM_FRONTPANEL_VERSION);
 #endif
     fprintf (st, "\n\tHost Platform:");
 #if defined (__GNUC__) && defined (__VERSION__)
@@ -4418,7 +4422,7 @@ t_stat show_time (FILE *st, DEVICE *dptr, UNIT *uptr, int32 flag, char *cptr)
 {
 if (cptr && (*cptr != 0))
     return SCPE_2MARG;
-fprintf (st, "Time:\t%.0f\n", sim_time);
+fprintf (st, "Time:\t%.0f\n", sim_gtime());
 return SCPE_OK;
 }