Re-connects and schema

Re-connects moved out of connection.py and into api
Schema grabbed on init of API() and set.
Temporarily stuff into models and have transform grab it.
Dynamically create models

create a models.Models object which has attributes for every one of our
models.  On schema changes, models.Models will get swapped atomically.

models.Models.Instance would be our Instance model.
Schema format change

schema['tables'][tablename] was a list of columns.  Now it's a
dictionary containing table info.  Only key right now is 'columns' with
a list of columns.
Merge pull request #12 from comstud/mysqldb-dev

Re-connects and schema