admin/roles: context-specific role changes mark the context as dirty

And will force a reload of $USER->access for logged-in users that need
to read _this_ context. Much lower impact - still not a great idea to
edit assignments/caps on very busy courses, but impact should be low.

admin/roles/assign.php

@@ -225,6 +225,8 @@
                     }
                 }
             }
+            // force accessinfo refresh for users visiting this context...
+            mark_context_dirty($context->path);
 
         } else if ($remove and !empty($frm->removeselect) and confirm_sesskey()) {
 
@@ -259,6 +261,8 @@
                     }
                 }
             }
+            // force accessinfo refresh for users visiting this context...
+            mark_context_dirty($context->path);
 
         } else if ($showall) {
             $searchtext = '';

admin/roles/override.php

@@ -112,6 +112,10 @@
                 }
             }
         }
+
+        // force accessinfo refresh for users visiting this context...
+        mark_context_dirty($context->path);
+
         redirect($baseurl);
     }