alters the position of 'read' bit markers

tweaks the 'makrer' labelling of bits that are 'read' to be just before the falling edge of the clock (where the are actually read) rather than on the rising edge - see issue saleae#2 of the original Saleae analyser

src/SWDTypes.cpp

@@ -153,7 +153,8 @@ void SWDOperation::AddMarkers( SWDAnalyzerResults* pResults )
                                  pResults->GetSettings()->mSWCLK );
         // read
         else
-            pResults->AddMarker( bi->rising, bi->state_rising == BIT_HIGH ? AnalyzerResults::One : AnalyzerResults::Zero,
+            pResults->AddMarker( (U64)(bi->rising + ((bi->falling - bi->rising) * 0.8)), // just before the falling edge [captain]
+                                 bi->state_rising == BIT_HIGH ? AnalyzerResults::One : AnalyzerResults::Zero,
                                  pResults->GetSettings()->mSWCLK );
     }
 }