Remove $Id$ from file license headers
Use "public static" for consistency
Use strict equality check in AnnotationDriver factory method
Clean up sandbox example documents

Don't use MD5 binary BSON type for storing MD5 strings, since they aren't raw bytes. Also, use ArrayCollection in lieu of arrays for default values of Reference/EmbedMany fields.
Use canonical name for DocumentManagerHelper in command classes

Also add docblocks to DocumentManagerHelper.
Clean up sandbox scripts

The only functional changes are relying on Composer to autoload example document classes and simplying the HelperSet configuration.