Set maxsplit=2 for :hint.

This supports things like :hint all spawn -v echo as '-v echo' will be
passed as a single unit to spawn rather than -v being interpreted as a
flag for :hint.

Resolves #797.

Note that, while `:hint --rapid all spawn -v` echo works,
`:hint all --rapid spawn -v echo` does not (this did not work before
either).

qutebrowser/browser/hints.py

@@ -779,7 +779,7 @@ class HintManager(QObject):
             webview.openurl(url)
 
     @cmdutils.register(instance='hintmanager', scope='tab', name='hint',
-                       star_args_optional=True)
+                       star_args_optional=True, maxsplit=2)
     @cmdutils.argument('win_id', win_id=True)
     def start(self, rapid=False, group=webelem.Group.all, target=Target.normal,
               *args, win_id):

tests/integration/features/hints.feature

@@ -50,12 +50,11 @@ Feature: Using hints
         And I run :follow-hint a
         Then the message "Command exited successfully." should be shown
 
-    @xfail
     Scenario: Using :hint spawn with flags (issue 797)
         When I open data/hints/html/simple.html
         And I run :hint all spawn -v echo
         And I run :follow-hint a
-        Then the message "Command exited successfully" should be shown
+        Then the message "Command exited successfully." should be shown
 
     Scenario: Yanking to primary selection without it being supported (#1336)
         When selection is not supported