Fix eventData size limit of 255 bytes

* Overflow could be easily triggered by sending a long message
via the message center

Source/Processors/GenericProcessor/GenericProcessor.cpp

@@ -750,7 +750,7 @@ void GenericProcessor::addEvent (MidiBuffer& eventBuffer,
                                  int sampleNum,
                                  uint8 eventId,
                                  uint8 eventChannel,
-                                 uint8 numBytes,
+                                 int numBytes,
                                  uint8* eventData,
                                  bool isTimestamp)
 {

Source/Processors/GenericProcessor/GenericProcessor.h

@@ -381,7 +381,7 @@ public:
                            int sampleNum,
                            uint8 eventID = 0,
                            uint8 eventChannel = 0,
-                           uint8 numBytes = 0,
+                           int numBytes = 0,
                            uint8* data = 0,
                            bool isTimestamp = false);