add tutorial chapter 'handling of spatial data'

[pat-s]

Clean version of #121

[pat-s]

@jakob-r can we merge this?

[pat-s]

@jakob-r thanks, typos and coding style issues are embarassing :no_mouth: mergable then? I have no rights to do so :smile:

[jakob-r]

From my side this can be merged. Let's wait a little and see if @larskotthoff or @berndbischl have a final word.

[pat-s]

@larskotthoff merge? :)

[larskotthoff]

Oh, am I doing the tutorial as well now? ;)

Tiny thing that needs to be changed.

[pat-s]

@larskotthoff seems to me you're doing everything, anytime, everywhere :stuck_out_tongue:

[larskotthoff]

Thanks, merging.