- Added Makefile.RHEL8 for RHEL8

- Added a interMessagePeriod to SINQController, pmacController and MasterMACSController. Also a iocsh command to modify this at runtime

sinqEPICSApp/src/SINQController.h

@@ -18,11 +18,15 @@ class epicsShareClass SINQController : public asynMotorController
 {
  public:
   SINQController(const char *portName, const char *SINQPortName, int numAxes, const int& extraParams=2);
-
+  asynStatus setInterMessageSleep(int messageSleep);
+ 
   friend class SINQAxis;
  protected:
   int motorMessageIsFromDriver_;
   int motorMessageText_;
+
+  int interMessageSleep; // minimum time between message to the controller in microseconds
+                         // for slowing down communication to weak controllers.....
 };