Add helper function to delete related tasks on deletion of sites, platforms & server nodes.
Prepare for server status, and fix removal of delete button from node forms.
Add function docs, and remove old platform listing code.
Issue #2040445: Provide a safe way to remove a server from the system.
Remove old hook documentation, hook_provision_args was last used in 1.x
Issue #2271211 by helmo: Re-introduce a fallback profile lookup.

Reason: profile unknown after D6 to D7 migrate - https://drupal.org/node/2285823