Offer the revision when the script is over its running time

Revising was reachable only after readers had reviewed it or the author had
left a note. Being ninety seconds over budget is a reason to revise on its
own, and the button now says how much it will cut.

trailer.html

@@ -317,8 +317,14 @@
 
       if (RUN.stage === "revising")
         out.push('<button type="button" class="btn" disabled>Rewriting…</button>');
-      else if (REVIEWS.length || Object.keys(NOTES).length)
-        out.push('<button type="button" class="btn" data-revise="1">Revise the whole script</button>');
+      else {
+        var over = (PKG.timing && Number(PKG.timing.over_by)) || 0;
+        if (REVIEWS.length || Object.keys(NOTES).length || over > 5)
+          out.push('<button type="button" class="btn' + (over > 5 ? ' primary' : '')
+            + '" data-revise="1">'
+            + (over > 5 ? 'Cut ' + Math.round(over) + ' seconds and revise'
+                        : 'Revise the whole script') + '</button>');
+      }
 
       if (unfilmed && !undrawn)
         out.push('<button type="button" class="btn primary" data-film="' + esc(meta.id)