SITL: added SIM_FLOW_DELAY parameter

libraries/SITL/SITL.cpp

@@ -64,6 +64,7 @@ const AP_Param::GroupInfo SITL::var_info[] PROGMEM = {
     AP_GROUPINFO("FLOW_ENABLE",   33, SITL,  flow_enable, 0),
     AP_GROUPINFO("TERRAIN",       34, SITL,  terrain_enable, 1),
     AP_GROUPINFO("FLOW_RATE",     35, SITL,  flow_rate, 10),
+    AP_GROUPINFO("FLOW_DELAY",    36, SITL,  flow_delay, 0),
     AP_GROUPEND
 };
 

libraries/SITL/SITL.h

@@ -83,6 +83,7 @@ public:
     AP_Int8  float_exception; // enable floating point exception checks
 	AP_Int8  flow_enable; // enable simulated optflow
 	AP_Int16 flow_rate; // optflow data rate (Hz)
+	AP_Int8  flow_delay; // optflow data delay
 	AP_Int8  terrain_enable; // enable using terrain for height
 
     // wind control