CSPACE 12: Second iteration of RELAX NG schema for defining and validating an entity...

CSPACE 12: Second iteration of RELAX NG schema for defining and validating an entity, and also - by way of example - a CollectionObject payload.  This iteration now defines a set of core fields common to every entity object, a base definition for each field in that object, and two different alternatives - one using infoBlocks, one without - for enclosing sets of related fields.  This set of schema now successfully validates a pair of test entity files, also included with this iteration.  There are also comments about how we might perform in-line validation using Schematron rules.