fileDownload session support edition

# Change log:
* add check session value function.
    * session value check function use ajax to get server values and sample of response body from server side.

      `{"resultCode":"SUCCESS","errorMsgs":null,"code":",1411101372971"}`
* the session key can be set in application on the server side.
   * I didn't delete variable name of [cookieXxxx] in this version, and use "cookieValue" for check session value.

# Why hacks it
When multiple to download file in a same session, the download of modal window wil be not appear, because the cookie value will be changed by other operation.
So I use the HTTP session to save multiple download status values.
Of caurse,  May be delete be used download status from session, but didn't implemente it in this version.