Gyuricska Milán / cloud

Using join method on the nodes list instead of string concatenation. Logging if monitor info unreachable or None in get_monitor_info method.

Turned off the autoescape for the variable which cointains the html tag.

Each node, which has unreachable monitor info shown in one error message.

The page now loads when the node can't reach the monitor info values e.g. cpu percent. It gets a default value 0. And if a node's monitor info unreachable shows
an error message.

Add new environment variable (MAX_NODE_CPU_RAM) in settings/base.py. Using this variable in dashboard/forms.py as maximal value of cpu cores.

commands: init command extended with default node, users, groups, permissions and detects kvm hardware acceleration presence.

* adds default node
* adds test groups: 'Administrators', 'Powerusers', 'Users'
* adds test users: 'admin', 'poweruser', 'user'
* adds KVM present notification for Administrator
* shares 'vm' network with groups

Suggestion to eleminate RequestContext: https://docs.djangoproject.com/en/1.11/ref/templates/upgrading/#django-template-loader

dashboard, circle: register django autocomplete light and load static content for FilteredSelectMultiple widget on the proper way

dashboard, circle, network, request: upgrade and rework autocompletion, remove deprecated 'pattern' from url patterns

Changes:
* Use argparse instead of optparse: https://docs.djangoproject.com/en/1.11/releases/1.10/#features-removed-in-1-10
* convert print to self.stdout.write(), Django documents suggest it: https://docs.djangoproject.com/en/1.11/howto/custom-management-commands/#module-django.core.management

dashboard, vm: fix user handling i tests, new Origin type cannot implicit convert to str, fix redirect_chain in 2FA tests, importing vm operation in __init_.py is unnecessary and and brokes the application

circle, common, dashboard, firewall, request: fix deprecated context and cache handling, get_models, and max_length type for ConnectCommand name

closes #467