Remove not implemented method.

src/Emulation.cpp

@@ -242,15 +242,6 @@ void Emulation::sendKeyEvent(QKeyEvent *ev)
     }
 }
 
-void Emulation::sendMouseEvent(int /*buttons*/, int /*column*/, int /*row*/, int /*eventType*/)
-{
-    // default implementation does nothing
-}
-
-/*
-   We are doing code conversion from locale to unicode first.
-*/
-
 void Emulation::receiveData(const char *text, int length)
 {
     bufferedUpdate();

src/Emulation.h

@@ -218,7 +218,7 @@ public Q_SLOTS:
      * Converts information about a mouse event into an xterm-compatible escape
      * sequence and emits the character sequence via sendData()
      */
-    virtual void sendMouseEvent(int buttons, int column, int line, int eventType);
+    virtual void sendMouseEvent(int buttons, int column, int line, int eventType) = 0;
 
     /**
      * Sends a string of characters to the foreground terminal process.