Adding local OS detection (Windows, Posix) to BoundEnv class.

Note: I've kept it simple. We could expand this to more platforms as per this link, but there's no use case currently: http://rbjl.net/35-how-to-properly-check-for-your-ruby-interpreter-version-and-os
Added write/rollback methods of local hosts file for Windows format (mirroring what is currently done for local Unix). Requires to run cmd prompt as admin, and aborts with error msg if you can't write it.

Notes:
1) It may make sense to extract hosts file writer into it's own class. I didn't do this in order to preserve existing code structure.
2) Alternatively, it may make sense to remove local host file modification altogether, or at least provide and option to disable it. This will be a pain for enterprise Windows users who don't have local admin privileges (the poor chaps!)
Added Windows Vulcanizer, which addresses a known limitation in Bundler when copying/deploying code cross-platform.
- Added remote library dos2unix to Windows vulcanizer
- Remote calls 'dos2unix' after code file transfer
- Remote calls 'dos2unix' after config file transfers during config step (always calls this regardless of local windows / unix, but forces command with '|| true' suffix so it won't fail if dos2unix isn't installed).
Dalli should be the default gem for memcached. Memcache-client has been deprecated since 2010.
Missed a comment in the file
Merge pull request #289 from johnnyshields/memcached-dalli

Dalli should be the default gem for memcached
Updated ruby-build and the latest default ruby to get security fixes.
Fixed #287: Failure converting from RVM to ruby-build.
Fixed monit config for Sidekiq, which shouldn't be using binstubs.
Fixed #281: sidekiq refuses to run with stdin: is not a tty error
Preparing for the 2.2.2 release.
Bumped the version number.
Updated the sample gemsources.
Improvements to rubber:tail_logs

- Include host name at the beginning of each line
- Insert blank line between log entries from different hosts
- Gracefully exit when ctrl-c is pressed
Upgraded to the latest Ubuntu 12.04 LTS image.
Don't fail starting a service if it's already running.
Preparing for the 2.2.3 release.
Merge pull request #296 from willkoehler/tail_logs_improvements

Improvements to rubber:tail_logs
'service mysql status' doesn't return an error status code if the server isn't running, so this check won't work as intended.