Upstream API changes

• feat: moved to click; added fava-miler as console-script. [Red S]
• feat: Replace 9999-12-31 with the string no expiry. [Red S]
• chore: enable fava context and filters. Also upstream favaledger updates. [Red S]

Move to fava's new querytable API

This release uses fava-1.18's new querytable API. Support for the older API has been deprecated.

Handle no expiry; Upstream API

Merge pull request #5 from redstreet/update

beancount api get_commodity_map() -> get_commodity_directives()