Add "/" to begin of OSC address if user doesn't. closes #6

OSC2AHK/dllmain.cpp

@@ -164,10 +164,15 @@ DLLEXPORT int close(unsigned int clearListeners)
 
 DLLEXPORT int addListener(LPCSTR address_, unsigned int messageID_, unsigned int dataType_)
 {
+    std::string addrStr(address_);
+
+    //All OSC addresses have to start with a '/'
+    if (addrStr[0] != '/') addrStr.insert(0, "/");
+
     OutputDebugString(L"addListener: address=");
-    OutputDebugStringA(address_);
+    OutputDebugStringA(addrStr.c_str());
     OutputDebugString(L"\r\n");
-    listeners.push_back(Listener{ std::string(address_), dataType_, messageID_ });
+    listeners.push_back(Listener{ addrStr, dataType_, messageID_ });
     return 0;
 }