Adding caa-indexer recipe

The caa-indexer::default recipe installs the caa-indexer and all
dependencies on a machine, and runs it using daemontools.

The caa-indexer::rabbitmq recipe should be used on a machine
running RabbitMQ, and will create the necessary accounts and virtual
host for the caa-indexer to work.
Merge branch 'musicbrainz-server-virtualmachine' into caa-indexer

Conflicts:
	.gitmodules