v2.0

Refactored scripts to meet "Make each program do one thing well" philosophy.

Changelog:

• Only one ssh process is spawn in both client and server (this will reduce server load)
• Changed link-with-server.sh to loop forever in order to response connection losses faster (reconnection takes 45 seconds at most)
• Removed key generation and key registration functions.
• Started using aktos-bash-lib