[Robustness] be robust against the global setTimeout changing.

Fixes #292.

Author: ljharb

lib/test.js

@@ -12,6 +12,7 @@ var nextTick = typeof setImmediate !== 'undefined'
     ? setImmediate
     : process.nextTick
 ;
+var safeSetTimeout = setTimeout;
 
 inherits(Test, EventEmitter);
 
@@ -119,7 +120,7 @@ Test.prototype.plan = function (n) {
 Test.prototype.timeoutAfter = function(ms) {
     if (!ms) throw new Error('timeoutAfter requires a timespan');
     var self = this;
-    var timeout = setTimeout(function() {
+    var timeout = safeSetTimeout(function() {
         self.fail('test timed out after ' + ms + 'ms');
         self.end();
     }, ms);