Log message:
Add SHA512 digests for distfiles for databases category

Problems found with existing distfiles:
	distfiles/D6.data.ros.gz
	distfiles/cstore0.2.tar.gz
	distfiles/data4.tar.gz
	distfiles/sphinx-2.2.7-release.tar.gz
No changes made to the cstore or mariadb55-client distinfo files.

Otherwise, existing SHA1 digests verified and found to be the same on
the machine holding the existing distfiles (morden).  All existing
SHA1 digests retained for now as an audit trail.

Log message:
Import py27-mongo-2.7.1 as databases/py-mongo.

The PyMongo distribution contains tools for interacting with MongoDB
database from Python.

The bson package is an implementation of the BSON format for Python.
The pymongo package is a native Python driver for MongoDB.
The gridfs package is a gridfs implementation on top of pymongo.