Flatten GUI tree somewhat

The very deep tree structure didn't really aggree with me, sorry. This
makes the core module rather large, but on the other hand that just
highlights that it is rather large.

gui/syncthing/core/httpErrorDialogView.html

@@ -0,0 +1,5 @@
+<modal id="httpError" status="danger" icon="exclamation-sign" title="{{'Connection Error' | translate}}">
+	<p translate>
+	  Syncthing seems to be experiencing a problem processing your request. Please refresh the page or restart Syncthing if the problem persists.
+	</p>
+</modal>