Allow use of non-numeric (e.g. UUID) values for ObjectIdentity.getIdentifier()

Prior to this commit, the ObjectIdentity id had to be a number. This
commit allows for domain objects to use UUIDs as their identifier. The
fully qualified class name of the identifier type can be specified
in the acl_object_identity table and a ConversionService can be provided
to BasicLookupStrategy to convert from String to the actual identifier
type.

There are the following other changes:

 - BasicLookupStrategy has a new property, aclClassIdSupported, which
 is used to retrieve the new column from the database. This preserves
 backwards-compatibility, as it is false by default.

 - JdbcMutableAclService has the same property, aclClassIdSupported,
 which is needed to modify the insert statement to write to the
 new column. Defaults to false for backwards-compatibility.

 - Tests have been updated to verify both the existing functionality
 for backwards-compatibility and the new functionality.

Fixes gh-1224

acl/src/main/resources/createAclSchemaOracle.sql

@@ -43,7 +43,7 @@ END;
 CREATE TABLE acl_object_identity (
     id NUMBER(38) NOT NULL PRIMARY KEY,
     object_id_class NUMBER(38) NOT NULL,
-    object_id_identity NUMBER(38) NOT NULL,
+    object_id_identity NVARCHAR2(36) NOT NULL,
     parent_object NUMBER(38),
     owner_sid NUMBER(38),
     entries_inheriting NUMBER(1) NOT NULL CHECK (entries_inheriting in (0, 1)),