Move examples to the oemof_examples repo

[uvchik]

Move well documented examples to the oemof_examples repo. It is a good and central place for examples and people will be aware of the different tools of the oemof cosmos.

[uvchik]

See oemof/oemof-examples#35

[SabineHaas]

Thank you, Uwe!

I leave this issue for the next release for the second example, okay?