React to CreateSequenceNode changes, fix cycle behavior

And change the defaults for start, min, and max to 1, 1 and Long.MAX_VALUE, respectively.

The default changes have no affect on existing Sequences as all the values are determined at DDL time and then saved.

As I was mucking in the area, go ahead and fix #805 by being a little smarter about the value computation.

Note: FoundationDB/sql-parser#96 must go in first.