Re-insert the previously removed character(s).

def reverseCommit(self):
        """
        Re-insert the previously removed character(s).
        """
        # Get the text cursor for the current document.
        tc = self.qteWidget.textCursor()

        # Mark the previously inserted text and remove it.
        tc.setPosition(self.cursorPos0, QtGui.QTextCursor.MoveAnchor)
        tc.setPosition(self.cursorPos1, QtGui.QTextCursor.KeepAnchor)
        tc.removeSelectedText()
        tc.setPosition(self.cursorPos0, QtGui.QTextCursor.MoveAnchor)

        # Apply the changes.
        self.qteWidget.setTextCursor(tc)