New console commands

We need to add commands for creating and dropping document databases and collections. I added methods to DocumentManager for creating/dropping databases and collections for documents. We have the command for creating indexes, now we need the same for databases and collections.

The reason is because you can specify configuration for the collection in the mapping that is used on collection creation:

/** @Document(collection={"name"="collname", "capped"="true", "max"="10"}) */
class Document
{}