Add stop command (ctrl-s)

TODO

@@ -383,9 +383,6 @@ Find backward, ignore case (command find_backward_ic, alias ibfind).
 [n]R
 Reload tab n or current tab if n is omitted without using any cached data (command reload_bypass_cache, aliases: refull).
 
-[n]C-s
-Stop loading of tab n or of current tab is [n] is omitted (command stop_loading, aliases: stop, st).
-
 [n]=
 Zoom to n percent or to 100% if n is omitted(command zoom, aliases: z).
 

qutebrowser/browser/curcommand.py

@@ -183,6 +183,12 @@ class CurCommandDispatcher(QObject):
             printdiag = QPrintDialog(tab)
             printdiag.open(lambda: tab.print(printdiag.printer()))
 
+    @cmdutils.register(instance='mainwindow.tabs.cur')
+    def stop(self, count=None):
+        """Stop loading of tab [n] or of current tab."""
+        tab = self._tabs.cntwidget(count)
+        tab.stop()
+
     @cmdutils.register(instance='mainwindow.tabs.cur')
     def back(self, count=1):
         """Go back in the history of the current tab.

qutebrowser/config/configdata.py

@@ -624,6 +624,7 @@ DATA = OrderedDict([
         ('<PgUp>', '${<Ctrl-B>}'),
         ('<PgDown>', '${<Ctrl-F>}'),
         ('<Ctrl-h>', 'home'),
+        ('<Ctrl-s>', 'stop'),
     )),
 
     ('keybind.insert', sect.ValueList(