Allowing non-institution site admins to publish (bug #1255361)

Currently, if a site admin tries to edit an institution page and
attach a file to a block (eg image block) and they don't belong to
that institution, the process fails.

Have altered the can_publish_artefact() to allow those that can edit
institutions to be allowed to also publish.

Change-Id: I05a2160e84814add067019e4bde654a6ebd561b1
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/auth/user.php

@@ -1032,7 +1032,7 @@ class User {
             if ($i == 'mahara') {
                 return $this->get('admin');
             }
-            return $this->in_institution($i);
+            return $this->in_institution($i) || $this->can_edit_institution($i);
         }
 
         if (!$group = $a->get('group')) {