Small cleanup of how we handle using fork vs vfork

cbits/runProcess.c

@@ -85,7 +85,7 @@ runInteractiveProcess (char *const args[],
     // signal and keeps restarting indefinitely.
     stopTimer();
 
-    switch(pid = fork())
+    switch(pid = myfork())
     {
     case -1:
         unblockUserSignals();

include/runProcess.h

@@ -29,8 +29,12 @@
 #include <vfork.h>
 #endif
 
-#ifdef HAVE_VFORK
-#define fork vfork
+#if defined(HAVE_WORKING_VFORK)
+#define myfork vfork
+#elif defined(HAVE_WORKING_FORK)
+#define myfork fork
+#else
+#error Cannot find a working fork command
 #endif
 
 #ifdef HAVE_SIGNAL_H