don't flush redis on start, don't delete images on start

I think we initially did this to debug some problems with broken data in redis

modules/cache.js

@@ -2,7 +2,7 @@ var config = require("./config");
 var redis = null;
 var fs = require("fs");
 
-// sets up redis connection, calls clear_cache
+// sets up redis connection
 function connect_redis() {
   console.log("connecting to redis...");
   if (process.env.REDISCLOUD_URL) {
@@ -14,7 +14,6 @@ function connect_redis() {
   }
   redis.on("ready", function() {
     console.log("Redis connection established.");
-    clear_cache();
   });
   redis.on("error", function (err) {
     console.error(err);
@@ -26,34 +25,34 @@ function connect_redis() {
 
 
 // flushes redis, deletes faces + helms
-function clear_cache() {
-  console.log("Flushing redis");
-  redis.flushall();
-  console.log("Deleting all faces + helms...");
-  fs.readdir(config.faces_dir, function(err, files) {
-    if (err) {
-      console.error(err);
-    } else {
-      for (var i in files) {
-        var file = files[i];
-        if (file[0] != ".") {
-          // delete face file
-          fs.unlink(config.faces_dir + file, function(err){
-            if (err) {
-              console.error(err);
-            }
-          });
-          // delete helm file, we assume this exists as well
-          fs.unlink(config.helms_dir + file, function(err){
-            if (err) {
-              console.error(err);
-            }
-          });
-        }
-      }
-    }
-  });
-}
+// function clear_cache() {
+//   console.log("Flushing redis");
+//   redis.flushall();
+//   console.log("Deleting all faces + helms...");
+//   fs.readdir(config.faces_dir, function(err, files) {
+//     if (err) {
+//       console.error(err);
+//     } else {
+//       for (var i in files) {
+//         var file = files[i];
+//         if (file[0] != ".") {
+//           // delete face file
+//           fs.unlink(config.faces_dir + file, function(err){
+//             if (err) {
+//               console.error(err);
+//             }
+//           });
+//           // delete helm file, we assume this exists as well
+//           fs.unlink(config.helms_dir + file, function(err){
+//             if (err) {
+//               console.error(err);
+//             }
+//           });
+//         }
+//       }
+//     }
+//   });
+// }
 
 // sets the date of the face file belonging to +hash+ to now
 // the helms file is ignored because we only need 1 file to read/write from