Add JuiceSSH plugin support for SPA/fwknop

Rabin Yasharzadehe suggested to the fwknop mailing list that fwknop support be added to JuiceSSH via their new plugins capability:

http://www.androidpolice.com/2014/06/18/popular-android-ssh-client-juicessh-adds-support-for-community-plugins-and-you-can-get-three-of-them-right-now/

该提问来源于开源项目：mrash/fwknop