Fix https://github.com/julianhyde/optiq/issues/85 "Adding a table to the root schema causes breakage in OptiqPrepareImpl".

Conflicts:
	core/src/main/java/net/hydromatic/optiq/prepare/OptiqPrepareImpl.java
	core/src/test/java/net/hydromatic/optiq/test/OptiqSuite.java
	core/src/test/java/net/hydromatic/optiq/test/TableInRootSchemaTest.java
Fix JDBC column, table, schema names for when the table is not in a schema of depth 1.