C2MS13 — Remove Unused Documentation from Model Classes

In the model, Message Security (part of Message Envelop) has text under the model class->specification->documentation that is superfluous.

All such 'documentation' should only exist in notes on the diagram or as text in the spec document (until we move to a model-based spec in 2.x). For now, remove this, as it was used to capture information during development. When removing, perform an analysis to see if that text should be moved to a note on the diagram or placed in the spec document, instead. Otherwise, simply remove.

Message Security (part of Message Envelop)
"a sender-identity type (JWT/SAML) String. Note that this field could be a group.

SECURITY-CONTROL-INFO with 0 = no encryption/signing 1 = digital signature, 2 = mac, 3 = … and 7+ = Mission Defined."