Small fix for related name
Cleanup
Renaming Leaf -> Node.
More consistency in parameter naming.
Better variable names in parse
Parse_expr -> parse_node
expr -> node.
var names
Fixing var names in postgres_ext
Few more cleanups.
Expr -> Expression
Some code cleanups for pep8
pep8 fixes for gfk.
cleanups in migrate
Few more pep8-type cleanups.