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
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
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
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!