Dev meeting 12/2019 issue auction

[jnnr]

A collection of issues for the issue auction at the 2019 winter dev meeting.

Labeled as Bug:
https://github.com/oemof/oemof/issues/630
https://github.com/oemof/oemof/issues/542
https://github.com/oemof/oemof/issues/187

Labeled as decision wanted:
https://github.com/oemof/oemof/issues/567
https://github.com/oemof/oemof/issues/557
https://github.com/oemof/oemof/issues/556
https://github.com/oemof/oemof/issues/406
https://github.com/oemof/oemof/issues/140

Labeled as help wanted:
https://github.com/oemof/oemof/issues/597 and https://github.com/oemof/oemof/issues/544
https://github.com/oemof/oemof/issues/514

Labeled as oemof-solph:
https://github.com/oemof/oemof/issues/528

Labeled as enhancement:
https://github.com/oemof/oemof/issues/560
https://github.com/oemof/oemof/issues/502

demandlib:
oemof/demandlib#17
oemof/demandlib#7
oemof/demandlib#2

oemof-examples
oemof/oemof-examples#2 and oemof/oemof-examples#26
oemof/oemof-examples#42
oemof/oemof-examples#20
oemof/oemof-examples#27

other:
https://github.com/oemof/oemof/issues/461
https://github.com/oemof/oemof/issues/517
https://github.com/oemof/oemof/issues/555
https://github.com/oemof/oemof/pull/609
https://github.com/oemof/oemof/pull/592
oemof/oemof-visio#3

PRs with 'decision_wanted' or 'bug' label
https://github.com/oemof/oemof/pull/558
https://github.com/oemof/oemof/pull/614
https://github.com/oemof/oemof/pull/627
https://github.com/oemof/oemof/pull/482