1.5.0

Introducing (in alpha) "Workers group":

• A global "group like" cluster, that execute different exploits in different machines
• "xfarm worker" command to add a new worker to the cluster, can be demonized with -d and killed with --kill
• "xfarm submit" to push and assign the exploit to the workers
• Timeout assigned, workers registered and exploits executed by the workes viewable on the WebUI

Introducing also minor fixes on xploit execution and push operation for exploits.

Full Changelog: 1.4.0...1.5.0