Add caching to minify

.gitignore

@@ -9,3 +9,4 @@ node_modules
 *.cert
 *.key
 torlist
+www/cache

lib/web/webserver.js

@@ -1,4 +1,5 @@
 var path = require("path");
+var fs = require("fs");
 var net = require("net");
 var express = require("express");
 var webroot = path.join(__dirname, "..", "www");
@@ -274,7 +275,13 @@ module.exports = {
         app.use(express.cookieParser());
 
         if (Config.get("http.minify")) {
-            app.use(require("express-minify")());
+            var cache = path.join(__dirname, "..", "..", "www", "cache")
+            if (!fs.existsSync(cache)) {
+                fs.mkdirSync(cache);
+            }
+            app.use(require("express-minify")({
+                cache: cache
+            }));
             Logger.syslog.log("Enabled express-minify for CSS and JS");
         }
         /* Order here is important