Implement all KeyStore methods except for password generation.

* Add all relevant message constants.
* Implement the messaging to send/retrieve key info.
* Implement _Flatten/_Unflatten for sending flat BKey objects.
* Remove application list from BKey, the key can't only differ by
  allowed applications as the identifiers would still collide, so the
  comparison isn't needed to uniquely identify the key. The applications
  can be enumerated via the BKeyStore instead.

headers/private/app/RegistrarDefs.h

@@ -122,6 +122,25 @@ enum {
 	B_REG_GET_USER_GROUPS					= 'rgug',
 	B_REG_UPDATE_USER						= 'ruus',
 	B_REG_UPDATE_GROUP						= 'rugr',
+
+	// KeyStore requests
+	B_REG_GET_KEY							= 'rgtK',
+	B_REG_GET_NEXT_KEY						= 'rgnK',
+	B_REG_ADD_KEY							= 'radK',
+	B_REG_REMOVE_KEY						= 'rrmK',
+	B_REG_ADD_KEYRING						= 'raKR',
+	B_REG_REMOVE_KEYRING					= 'rrKR',
+	B_REG_GET_NEXT_KEYRING					= 'rnKR',
+	B_REG_SET_MASTER_KEY					= 'rsMK',
+	B_REG_REMOVE_MASTER_KEY					= 'rrMK',
+	B_REG_ADD_KEYRING_TO_MASTER				= 'rarM',
+	B_REG_REMOVE_KEYRING_FROM_MASTER		= 'rrrM',
+	B_REG_GET_NEXT_MASTER_KEYRING			= 'rnrM',
+	B_REG_IS_KEYRING_ACCESSIBLE				= 'riaR',
+	B_REG_REVOKE_ACCESS						= 'rvaR',
+	B_REG_REVOKE_MASTER_ACCESS				= 'rvaM',
+	B_REG_GET_NEXT_APPLICATION				= 'rnKA',
+	B_REG_REMOVE_APPLICATION				= 'rrKA',
 };
 
 // B_REG_MIME_SET_PARAM "which" constants