Update quickbooks.py

Added a tool to flatten transaction lines into a list of lists where one general ledger line gets a list, whose items are attributes that appear in the "General Ledger" report, plus a few more. I haven't implemented all the objects, but I will do that soon.

If you're looking to contribute, what I need most is a working prototype for operations other than Query, which is all I'm using right now. If you can create one successful "Read", "Update", "Create", or "Delete" query method, I will happily clone it for the other objects.