First pass at Chef Solo provisioner.
Make JSON attributes work with real JSON!
Rename configuration `cookbook_paths` to `cookbooks_paths` to
conform to Vagrant wording.
Remove configuration `cookbook_path` to simplify some things.
Implement `avoid_sudo` configuration option.
Implement `skip_install` configuration to skip Chef installation.
Remove errant die statement.
Rename configuration `avoid_sudo` to `prevent_sudo`
Merge remote-tracking branch 'upstream/master' into provisioner-chef-solo

Conflicts:
	config.go

Add the chef-solo provisioner back to config.go.
Fix import path for chef-solo provisioner.
Add basic test file for provisioner-chef-solo.
Merge remote-tracking branch 'upstream/master' into provisioner-chef-solo
Improve logging.
Correct behavior for undefined recipe list.
Correct package name to upstream repo.
Remove redundant code and clean up some string concatenation.
Clean up Say statements.
Remove debugging statement.
packer/plugin: confirm cleanup at first signal received
builder/digitalocean: send a "shutdown" before snapshotting

Instead of pulling the plug on a droplet with the "poweroff" command,
we first send a soft shutdown to the API, then we poweroff to allow
the snapshot to properly complete.

Sending just a shutdown and then snapshotting wasn't as reliable as
sending the poweroff manually, for reasons unknown to me.

This fixes #332.
Bump Ubuntu 12.04.2 to 12.04.3

Ubuntu has removed the 12.04.2 release ISOs from their mirrors when they released 12.04.3. This impacted the URL and the Checksum contained in the example.json which returned an HTTP 404 from Ubuntu's Mirrors.
Merge pull request #342 from masteinhauser/patch-1

website: bump Ubuntu example from 12.04.2 to 12.04.3
Merge pull request #338 from mitchellh/signal-confirm

main: confirm cleanup at first signal received
Update CHANGELOG
Actual md5sum as Ubuntu Hashesh webpage is out of date.