proper favicon, close #11

I also added a note about the default parameter for skins

modules/config.js

@@ -1,16 +0,0 @@
-var config = {
-  min_size: 1,               // < 1 will (obviously) cause crash
-  max_size: 512,             // too big values might lead to slow response time or DoS
-  default_size: 160,         // size to be used when no size given
-  local_cache_time: 30,      // seconds until we will check if the image changed. should be > 60 to prevent mojang 429 response
-  browser_cache_time: 30,    // seconds until browser will request image again
-  http_timeout: 3000,        // ms until connection to mojang is dropped
-  cleaning_interval: 3,      // seconds interval: deleting images if disk size at limit
-  cleaning_limit: 10240,     // minumum required available KB on disk to trigger cleaning
-  cleaning_amount: 50000,    // amount of avatar (and their helm) files to clean
-  faces_dir: "skins/faces/", // directory where faces are kept. should have trailing "/"
-  helms_dir: "skins/helms/", // directory where helms are kept. should have trailing "/"
-  debug_enabled: true        // enables logging.debug
-};
-
-module.exports = config;