Add test cases for the proxy, and do some tiny fixes.

the fixes are:
1. add "content-type" in headers for when dealing with localresponse
2. make a more accurate tip for throttle rate when lower than 1
3. make the crtMgr funcionality a more independent one
4. uppercase the request header before sending it out

update the tip

lib/util.js

@@ -1,8 +1,11 @@
 var fs   = require("fs"),
     path = require("path"),
+    mime = require('mime-types'),
+    color = require('colorful'),
+    logUtil = require("./log"),
     exec = require('child_process').exec;
 
-
+const changeCase = require('change-case');
 // {"Content-Encoding":"gzip"} --> {"content-encoding":"gzip"}
 module.exports.lower_keys = function(obj){
     for(var key in obj){
@@ -34,7 +37,7 @@ module.exports.getAnyProxyHome = function(){
 
     if(!fs.existsSync(home)){
         try{
-            fs.mkdirSync(home,0777);
+            fs.mkdirSync(home, '0777');
         }catch(e){
             return null;
         }
@@ -48,7 +51,7 @@ module.exports.generateCacheDir = function(){
     var rand      = Math.floor(Math.random() * 1000000),
         cachePath = path.join(util.getAnyProxyHome(),"./" + CACHE_DIR_PREFIX + rand);
 
-    fs.mkdirSync(cachePath,0777);
+    fs.mkdirSync(cachePath, '0777');
     return cachePath;
 }
 
@@ -60,7 +63,7 @@ module.exports.clearCacheDir = function(cb){
     if(isWin){
         exec("for /D %f in (" + dirNameWildCard + ") do rmdir %f /s /q",{cwd : home},cb);
     }else{
-        exec("rm -rf " + dirNameWildCard + "",{cwd : home},cb);        
+        exec("rm -rf " + dirNameWildCard + "",{cwd : home},cb);
     }
 }
 
@@ -102,4 +105,53 @@ module.exports.filewalker = function(root,cb){
 
         cb && cb.apply(null,[null,ret]);
     });
-}
+};
+
+/*
+* 获取文件所对应的content-type以及content-length等信息
+* 比如在useLocalResponse的时候会使用到
+*/
+module.exports.contentType = function (filepath) {
+    return mime.contentType(path.extname(filepath));
+};
+
+/*
+* 读取file的大小，以byte为单位
+*/
+module.exports.contentLength = function (filepath) {
+    try {
+        var stat = fs.statSync(filepath);
+        return stat.size;
+    } catch (e) {
+        logUtil.printLog(color.red("\nfailed to ready local file : " + filepath));
+        logUtil.printLog(color.red(e));
+        return 0;
+    }
+};
+
+module.exports.showRootInstallTip = function () {
+    logUtil.printLog(color.red("can not find rootCA.crt or rootCA.key"), logUtil.T_ERR);
+    logUtil.printLog(color.red("you may generate one by the following methods"), logUtil.T_ERR);
+    logUtil.printLog(color.red("\twhen using globally : anyproxy --root"), logUtil.T_ERR);
+    logUtil.printLog(color.red("\twhen using as a module : require(\"anyproxy\").generateRootCA();"), logUtil.T_ERR);
+    logUtil.printLog(color.red("\tmore info : https://github.com/alibaba/anyproxy/wiki/How-to-config-https-proxy"), logUtil.T_ERR);
+};
+
+/*
+* remove the cache before requering, the path SHOULD BE RELATIVE TO UTIL.JS
+*/
+module.exports.freshRequire = function (path) {
+    delete require.cache[require.resolve(path)];
+    return require(path);
+};
+
+module.exports.upper_keys = function (obj) {
+    var upperObject = {};
+    for(var key in obj) {
+        var upperKey = changeCase.headerCase(key);
+        upperObject[upperKey] = obj[key];
+    }
+
+    return upperObject;
+};
+