Long handling

[Jaymon]

Version 1.2.0 has Postgres return integer for any long value using a type adapter in python 2.7. Python 3 doesn't have this problem because long doesn't exist, so there actually isn't any good way to specify BIGINT which is a separate but related problem.

I think when python2 support is dropped then all the long stuff should just be removed, there are just really hairy parts:

• foreign keys and the _id primary key are set to long as the field type but then both SQLite and Postgres return int values when rows are pulled out of the db.
• long handling is inconsistent between python 2 and 3
• type can be set to long in the Field information but be an int when pulled from the db
• I don't think there is any way to actually specify BIGINT in python 3