Added tag 0.12.0 for changeset 7b26dda69a46
remove setup.cfg

We only build pure python on py3 these days.
pkg: prepare 0.12
cli/scheduler: allow to export/import schedule lists

This is done with pickles and the purpose is to make
migrations easier, not long-term archival.
cli/list-scheduled: remove a spurious host entry
inputs/moment: use a better name for the time-delta like operator
doc: small convergence between the readme and the full doc

A torough backport of recent README entries remain
to be done.
tox: use the `extras_require` entry
pkg: really fix the extras_require entry
doc/readme: provide debugging guidance
pkg: do not drag pystuck (heavy depedency) if not explicitly asked
inputs: provide a `moment` input type which accepts lisp expression for dates

The expressions are evaluated at de-serialization time (which means in
practice within the task when the inputs are read).
inputs: regroup the decoding logic into the input handling objects
inputs: regroup the encoding logic into the input handling objects
doc: fix byid call example
doc: add `list-scheduled` to the command output
api: put prepare after schedule
doc: tidy the schedule api call parameter names
doc: document the `prepare` api call