Fix for jira issue MONDRIAN-1056. Prevent a connection from loading all schemas

Fix for jira issue MONDRIAN-1056. Prevent a MondrianOlap4jConnection from loading all schemas.
* MondrianOlap4jDatabase now lazily loads its catalogs.
* MondrianOlap4jCatalog now loads schemas only upon a getSchemas call.
* MondrianOlap4jConnection lazily loads its schemaMap.
* FileRepository sets the CatalogName property when creating its connection.