Remove change_title signal in QWebPage.

When emitting it inside acceptNaviationRequest we don't know if javascript will
open a new window, so we could end up setting the title for the *wrong*
(current) tab.

It seems there isn't any good solution to this problem - in
QWebView.createWindow we won't know what the URL is - so we currently just
leave it blank.

qutebrowser/browser/webpage.py

@@ -44,11 +44,9 @@ class BrowserPage(QWebPage):
 
     Signals:
         start_download: Emitted when a file should be downloaded.
-        change_title: Emitted when the title should be changed.
     """
 
     start_download = pyqtSignal('QNetworkReply*')
-    change_title = pyqtSignal(str)
 
     def __init__(self, parent=None):
         super().__init__(parent)
@@ -305,5 +303,4 @@ class BrowserPage(QWebPage):
             objreg.get('tabbed-browser').tabopen(url, True)
             return False
         else:
-            self.change_title.emit(urlstr)
             return True

qutebrowser/widgets/webview.py

@@ -102,7 +102,6 @@ class WebView(QWebView):
         objreg.register('tab-{}'.format(tab_id), self.registry, scope='meta')
         page.linkHovered.connect(self.linkHovered)
         page.mainFrame().loadStarted.connect(self.on_load_started)
-        page.change_title.connect(self.titleChanged)
         self.urlChanged.connect(self.on_url_changed)
         page.mainFrame().loadFinished.connect(self.on_load_finished)
         self.loadProgress.connect(lambda p: setattr(self, 'progress', p))