Tests for catalog items versioning functionality.
Support logging VM credentials

- In JcloudsLocation, if config says so then log the password/privateKey
- Useful for when debugging failing to ssh (e.g. in vcloud-director!), 
  but config should never be used in production!
RebindOptions (in tests): make public

- Let RebindOptions be used in downstream projects
Adds YamlLauncher.launchAppYaml(Reader) for tests
Add tests for Postgres restart/rebind

- And changes Postgres connectSensors() to use
  connectServiceUpIsRunning(), given that was all
  the feed was doing anyway.
Add MongoDBRestartIntegrationTest
RebindOptions: declare fields public
Extracts AbstractBlueprintTest and marks MongoDbBlueprintTest as WIP
Adds SshjTool exec script async
ShellToolAbstractTset.execCommands: remove duplication
ssh-async: use long-polling

- Polling ssh command executes until either command completes,
  process no longer running, or timeout.
- Adds PROP_EXEC_TIMEOUT for control when ssh commands should timeout.
- Adds PROP_EXEC_ASYNC_POLLING_TIMEOUT for the long-polling of
  async exec, to timeout each poll.
install java: use async-ssh-exec
nextAvailablePort, give better error messages

Validate that the given argument is in the valid range for port numbers.
If not possible to find a port in the valid range, throw a descriptive
exception message (instead of trying an invalid port number and getting
an IllegalArgumentException from the JRE)
Fix illegal argument in isPortAvailable

JRE docs say that the wildcard address can only be used on bind()
operations, but there's a case where we might use it in a connect()
call - this is undefined behaviour. Correct the code to pass in the
loopback address to connect() instead of the wildcard address.
Adds catalogItemId to UsageListener.onApplicationEvent
Formatting tweak to LICENSE

Hadrian Zbarcea noticed that the first lines of LICENSE are incorrectly
formatted - most likely due to copy-and-paste from the HTML page rather
than the text document.

No change to content.
Merge and close #410
This closes #345
Adds basic instructions for adding blueprints to and removing blueprints from the catalog
Rebased and relocated to new guide locations