Remove pre-KDE4-era unimplemented Konsole-specific extension

CSI 28 ; <c> t is a pre-KDE4-era (from the comments) extension to
the control codes, where <c> was supposed to set the text-color
on a tab. It is unimplemented since KDE4, and only generated
a debug-message when used. Remove its implementation and the
TODO's associated with "document the meaning of this parameter".
Because there's no point in documenting an unimplemented thing.

src/Emulation.h

@@ -272,16 +272,6 @@ Q_SIGNALS:
     void zmodemDownloadDetected();
     void zmodemUploadDetected();
 
-    /**
-     * Requests that the color of the text used
-     * to represent the tabs associated with this
-     * emulation be changed.  This is a Konsole-specific
-     * extension from pre-KDE 4 times.
-     *
-     * TODO: Document how the parameter works.
-     */
-    void changeTabTextColorRequest(int color);
-
     /**
      * This is emitted when the program (typically editors and other full-screen
      * applications, ones that take up the whole terminal display), running in

src/Vt102Emulation.cpp

@@ -676,7 +676,7 @@ void Vt102Emulation::processToken(int token, int p, int q)
                                break;
 
     // change tab text color : \e[28;<color>t  color: 0-16,777,215
-    case token_csi_ps('t',   28) : Q_EMIT changeTabTextColorRequest      ( p        );          break;
+    case token_csi_ps('t',   28) : /* IGNORED: konsole-specific KDE3-era extension, not implemented */ break;
 
     case token_csi_ps('K',   0) : _currentScreen->clearToEndOfLine     (          ); break;
     case token_csi_ps('K',   1) : _currentScreen->clearToBeginOfLine   (          ); break;

src/session/Session.cpp

@@ -123,7 +123,6 @@ Session::Session(QObject *parent)
     });
     connect(_emulation, &Konsole::Emulation::zmodemDownloadDetected, this, &Konsole::Session::fireZModemDownloadDetected);
     connect(_emulation, &Konsole::Emulation::zmodemUploadDetected, this, &Konsole::Session::fireZModemUploadDetected);
-    connect(_emulation, &Konsole::Emulation::changeTabTextColorRequest, this, &Konsole::Session::changeTabTextColor);
     connect(_emulation, &Konsole::Emulation::profileChangeCommandReceived, this, &Konsole::Session::profileChangeCommandReceived);
     connect(_emulation, &Konsole::Emulation::flowControlKeyPressed, this, &Konsole::Session::updateFlowControlState);
     connect(_emulation, &Konsole::Emulation::primaryScreenInUse, this, &Konsole::Session::onPrimaryScreenInUse);
@@ -695,11 +694,6 @@ void Session::updateFlowControlState(bool suspended)
     }
 }
 
-void Session::changeTabTextColor(int i)
-{
-    qCDebug(KonsoleDebug) << "Changing tab text color is not implemented " << i;
-}
-
 void Session::onPrimaryScreenInUse(bool use)
 {
     _isPrimaryScreen = use;

src/session/Session.h

@@ -765,14 +765,6 @@ private Q_SLOTS:
 
     void sessionAttributeRequest(int id, uint terminator);
 
-    /**
-     * Requests that the color the text for any tabs associated with
-     * this session should be changed;
-     *
-     * TODO: Document what the parameter does
-     */
-    void changeTabTextColor(int);
-
 private:
     Q_DISABLE_COPY(Session)