eNMS v4.2

• Add Network builder mechanism
• Add 3D visualization of network devices
• Extend Devices and Links with subclass / custom properties and a separate tab in the UI, the same way services work.
• Remove deep_services function used for export, use service.children relationship instead.
• Dont subclass SQLAlchemy Column following advice of SQLAlchemy creator.
• Make corrupted edges deletion mechanism a troublehooting snippet instead of a button in the admin panel.
• Move redis configuration in settings.json > "redis" key
• Add new mechanism to limit results in server-side drop-down list with filtering constraints.
• Limit superworkflow selection to workflows that contains the shared Placeholder service.
• Set trigger variable to "Regular Run" or "Parameterized Run" when service is triggered from the UI instead of "UI".
• Add SSH Proxy mechanism (multiple jump server in gateways property, gateway device subtype, priority
  tie-break mechanism)
• Consider runtime limiting user / all toggle mechanism in the restart service window.
• Move doc link to settings.json to allow custom doc links for plugins. Generate doc link in the jinja2 template
  instead of javascript (otherwise, wrong doc link until updated in js)
• Move tables refresh rate to settings.json to allow for custom refresh rates.
• New "Category" property / mechanism for the drop-down list of the site and workflow builder.
• Reinstate service selection with single left click (Ctrl no longer needed)
• Remove pytest, coverage, and travis dependencies.
• Reinstate single left click for node selection in workflow & site builder.
• Remove most union subquery in rbac_filter because a union of query yields a CompoundSelect
  SQLAlchemy object, and this is not compatible with using with_entites (via filtering properties kw).
• Fix export in bulk (the hierarchical display mode was not considered, all services inside a workflow
  were exported even when "hierarchical display" was selected)
• Add notification banner mechanism
• Remove default_access property, replace with "admin_only" boolean. Impact on migration.
• Make "run_service" rest api endpoint default to async True
• Update netmiko and napalm Backup services to load deferred row before updating. Impact on both services.
• Remove pathlib from requirements.txt
• Update workflow algorithm to not add services to priority queue in DxD mode if all are discarded.
• Update Ansible Service to use custom path in cwd argument of subprocess.check_output.
• Change default priority to 10 for services. Update of migration files required.
• Implement Cache Invalidation mechanism so that javascript/css files are reloaded at each release.
  Cache invalidation is activatated by setting "invalidate_cache" to true in settings.json.
  eNMS automatically renames the version folder in static / js and static / css to the version number
  stripped from its punctuation.
• Add new check box "Approved by an Admin user" in the Unix Command service. That box must be ticked by
  an admin user for the service to be allowed to run. A non-admin user cannot save a service if it is
  ticked, meaning that each time a Unix Command service is edited, it must be re-appproved.
• Add new timeout parameters for Scrapli service
• Always show security logs, even when logging is disabled. Add "allow_disable" (default: True) keyword argument
  to log function to prevent logs from being disabled if necessary.
• Add new 'deactivate_rbac_on_read' property in rbac.json, under 'advanced' key. Set to true by default.
  When true, eNMS no longers applies rbac for reading from the database. (=> better performances)
• Make the vendor, operating_system and model properties a custom list for devices, links and services,
  and category for sites and workflows. The drop-down list choices can be configured in properties.json > property_list key.
• Add support for renaming objects from the REST API (with key "new_name")
• Add limit to maximum number of nodes that can be displayed in site builder". Configurable via
  visualization.json > Network Builder > max_allowed_nodes
• Add new option to display site nodes as ellipses instead of images for better performances. Configurable via
  visualization.json > Network Builder > display_nodes_as_images
• Auto-update Vendor and Operating System property value of a new service in the workflow builder
  based on the values of these properties in the parent workflow.
• Add support for custom ordering in plugin tables (configurable by overriding the tableOrdering function in the
  table JS class)
• Add support for using device credentials in the Rest Call Service (impact on migration files:
  "username" / "password" => "custom_username" / "custom_password"). Don't allow using device credentials
  if the run method is set to "Run Once".
• Make webssh command configurable from settings / ssh section
• Add new label size property to configure label size in workflow and network builder
• Add new "Configuration" RBAC mode
• Make "sessions" an admin model (visible only to admin users)
• Update git service to support git clone, shallow clone and custom path to local folder (instead of hardcoded path to
  "network_data" folder)
• Update slack notification service to use newest slack_sdk library (instead of slackclient<2)
• Make scrapli connection arguments configurable from automation.json / scrapli / connection_args