Javascript mime type

There isn't MIMEType for javascript In `getMIMEType`, 
so javascript files don't have content type and
browser reconize the files as `text/plain` 

```shell
$ curl -I http://blog.outsider.ne.kr/resources/script/EAF4.js
HTTP/1.1 200 OK
Server: nginx/1.4.1
Content-Length: 20996
Connection: keep-alive
X-Powered-By: PHP/5.4.9-4ubuntu2
Last-Modified: Sat, 1 Mar 2014 19:00:00 GMT
Date: Sun, 9 Mar 2014 11:23:43  GMT
Expires: Mon, 10 Mar 2014 11:23:43 GMT
Cache-Control: max-age=86400
Pragma: cache
ETag: textcube-56c6dee0
```

after add `application/javascript` MIME type for `js`

```shell
$ curl -I http://blog.outsider.ne.kr/resources/script/EAF4.js
HTTP/1.1 200 OK
Server: nginx/1.4.1
Content-Type: application/javascript
Content-Length: 20996
Connection: keep-alive
Vary: Accept-Encoding
X-Powered-By: PHP/5.4.9-4ubuntu2
Last-Modified: Sat, 1 Mar 2014 19:00:00 GMT
Date: Sun, 9 Mar 2014 11:24:04  GMT
Expires: Mon, 10 Mar 2014 11:24:04 GMT
Cache-Control: max-age=86400
Pragma: cache
ETag: textcube-56c6dee0
```