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

samples/xml/contacts/src/main/java/sample/contact/DataSourcePopulator.java

@@ -95,11 +95,12 @@ public class DataSourcePopulator implements InitializingBean {
 		template.execute("CREATE TABLE ACL_CLASS("
 				+ "ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 100) NOT NULL PRIMARY KEY,"
 				+ "CLASS VARCHAR_IGNORECASE(100) NOT NULL,"
+				+ "CLASS_ID_TYPE VARCHAR_IGNORECASE(100),"
 				+ "CONSTRAINT UNIQUE_UK_2 UNIQUE(CLASS));");
 		template.execute("CREATE TABLE ACL_OBJECT_IDENTITY("
 				+ "ID BIGINT GENERATED BY DEFAULT AS IDENTITY(START WITH 100) NOT NULL PRIMARY KEY,"
 				+ "OBJECT_ID_CLASS BIGINT NOT NULL,"
-				+ "OBJECT_ID_IDENTITY BIGINT NOT NULL,"
+				+ "OBJECT_ID_IDENTITY VARCHAR_IGNORECASE(36) NOT NULL,"
 				+ "PARENT_OBJECT BIGINT,"
 				+ "OWNER_SID BIGINT,"
 				+ "ENTRIES_INHERITING BOOLEAN NOT NULL,"