Initialize just as much of Tcl that the expect C interface is happy

/* Compile with -lexpect -ltcl -ltclstub */

#include <stdio.h>
#include <tcl.h>
#include <expect.h>
#include <expect_tcl.h>

int main (int c, char **a) {
  int fd;
  char *argv[] = { "ssh", "localhost", NULL };

  Tcl_Interp *interp = Tcl_CreateInterp();
  if (Tcl_Init(interp) != TCL_OK) {
    fprintf(stderr, "Tcl_Init failed: %s\n", Tcl_GetStringResult(interp));
    return 1;
  }
  if (Expect_Init(interp) != TCL_OK) {
    fprintf(stderr, "Expect_Init failed: %s\n", Tcl_GetStringResult(interp));
    return 1;
  }
  fd = exp_spawnv ("ssh", argv); // <- this was segfaulting
  printf ("fd = %d\n", fd);
  return 0;
}