jp: dark and light theme: - `background` setting can now be used in sat.conf to indicate if the terminal use a `dark` or a `light` colour - if `background` is not set or set to `auto`, the background colour is autodetected - Jp.get_config (or CommandBase.get_config) method can now be used to retrieve a setting

# XXX: the Monkey Patch is here and not in src/__init__ to avoir issues with pyjamas compilation
# TODO: remove this when changes are merged in Wokkel
from sat_tmp.wokkel import install
install()