[FCS-35] Add crawler statistics
[FCS-35] Prepare for new autoscale model
[FCS-35] Message flow (TaskServer<->FCS) changed slightly
[FCS-35] Add speed assignment for TaskServers
[FCS-35] Crawlers removed from processing list only if they sent response
[FCS-35] Add task server statistics
[FCS-35] New crawlers assignment method
[FCS-35] New auto scaling method
[FCS-35] Small refactoring and docstrings in task_server
[FCS-35] Small fixes in task_server and autoscaling
Merge remote-tracking branch 'origin/master' into FCS-35

Conflicts:
	server/task_server.py
[FCS-35] Small fixes
[FCS-35] Fix unregister task server 404 error
Merge remote-tracking branch 'origin/master' into FCS-35

Conflicts:
	fcs/fcs/manager/forms.py
[FCS-35] Change autoscaling output