Merge pull request #1 from visualrevenue/master

List and Set improvements
Merge branch 'master' of git://github.com/visualrevenue/valid_model
Merge branch 'master' of github.com:visualrevenue/valid_model
Merge branch 'master' of github.com:yoshrote/valid_model
Toying with ways to generate ddl and queries
Patch descriptors of decorated classes. Map EmbeddedObject descriptors to a UDT