Use ''' instead of ''', which showed in template output

Issue observed during the development of familywall.com, in some conditions.
For some reason, using ''' instead fixed the issue.

mustache.js

@@ -40,7 +40,7 @@ var Mustache = function () {
     "<": "&lt;",
     ">": "&gt;",
     '"': '&quot;',
-    "'": '&#39;'
+    "'": '&apos;'
   };
 
   function escapeHTML(string) {
@@ -417,7 +417,7 @@ var Mustache = function () {
 
   return({
     name: "mustache.js",
-    version: "0.4.0-dev-familywall",
+    version: "0.4.1-dev-familywall",
 
     /*
       Turns a template and view into HTML