Lots of changes to the Builder/Client

- call the thing that connects to the servers a 'client'
  instead of a 'builder'
- rename a bunch of methods in the Client to get rid of
  camel case and make them a bit more descriptive (at least for
  the methods that are use publicly)
- semantic clarity for a few methods in Client
- rename 'request' module to 'client'
- add a client id automatically if ofx version is 103
- serialization and deserialization routines added to account/insitution.
  this greatly simplifies the cli.py