Move optimizer to linq4j, improve translation of strict functions
Mark SqlFunctions as @Deterministic (with some exceptions), support static final constants generated by linq4j
Upgrade to linq4j-0.3.
Upgrade maven-release-plugin.
Fix https://github.com/julianhyde/optiq/issues/252, "Scalar sub-query that returns 0 rows should become NULL value".
Provide an option to create root schema without the "metadata" schema.
Addressed review comments.