Clean up.

Make StdFrameworkConfig a private inner class.
[OPTIQ-305] Unit Test Failure on release candidates
[OPTIQ-314] Allow simple UDFs based on methods
While unifying a RelNode tree with a materialized view expression, switch representation to MutableRels.

MutableRel is similar to RelNode but mutable, not canonized, has a back links to its parent. Should make it easier to match the graph from leaves towards the root.
[OPTIQ-313] Query decorrelation fails
Remove deprecated methods.
[OPTIQ-340] Fix bug in SqlToRelConverter when push expressions in join condtions into Project.
Restore PushFilterPastJoinRule to RelDecorrelator; interim pending [OPTIQ-443] fix.
Fix push projector so that it doesn't attempt to cast children when a trivial project is removed.
add alternative OptiqSchema
Increase max precision and scale for numeric data to be 38

Fix import ordering