Crate

================

- Fix: show rows affected at `crash` on ``copy`` command

- crash: Added persistent history stored in platform dependent app-dir

- crash: Added support for multiple hosts for ``crash --hosts ...`` and the connect cmd

================

- Added SQL ``copy`` command support to `crash` crate cli

================

- crate layer: set working directory on layer instantiation instead of start hook

================

- fixed sqlalchemy datetime parsing that didn't work with crate >= 0.18.4 due
to the fixed datetime mapping.

================

- documented SQLAlchemy count() and group_by() support.

================

- http keepalive support

- uppercase command support for crash

- fixed python3.3 compatibility issue in crash