BROOKLYN-46: persist files with 600 permission
This closes #114
Adds CloudExplorer utility
This closes #103
BROOKLYN-15: enforce brooklyn.properties permissions

- brooklyn.properties must be something like 600; otherwise
  brooklyn will fail to start
Incorporate review comments (PRs #115 and #114)
This closes #115
Brooklyn starts if brooklyn.properties is missing
BrooklynNode copies files with 0600 permissions
This closes #122