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
refactor docs (no content or style changes)

inherit from a common base, move footer to an inclue, add comments to CSS for readability, and introduce a guide-base from which guide-normal inherits
combining style sheets and layouts, esp for user guide

user guide now has the same top+bottom branding as rest of site
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
Adds catalogItemId to UsageListener.onApplicationEvent
add icon links for twitter, github, and IRC; and use scss, because jekyll allows

just using a bit of scss, but it looks like it can help a lot to ensure consistent colors

also restored helvetica neue is font of choice
link to repo GUI *and* to dir, simplify (a bit) how url's are computed, and tidy guide downloads page
notes on use of rdiscount and pygments (neither helpful though)
remove duplicate jquery js load

this was breaking superfish; but things seemed to be working, so maybe we don't need superfish!
Adds basic instructions for adding blueprints to and removing blueprints from the catalog
Rebased and relocated to new guide locations
Updated catalog maintenance docs as per PR comments
restart/rebind tests: incorporate review comments