Thread for connection -> cancel button on progres -> update progress

New RoadMap:
  Server:
 - Change server password (done)
 - Enter maintenance mode (done)
 - Backup server (done)
 - Restore from backup (done)
 - Install license key (done)
 VM:
 - Install Xenserver tools (done)
 - Start in Recovery mode (done)
 Storage:
 - dettach/reattach/forget/delete (done)
 Other:
  - Install last patchs
  - New Storage -> Hardware HBA (done)
  - Send Ctrl alt del
- Clean code


Use text:
HOST_NOT_LIVE: Unreachable
VM_REQUIRES_SR: Cannot see required storage
HOST_NOT_ENOUGH_FREE_MEMORY: Host has not enough free memory
