[BP] Action-310 - reordering the BP

Hi all,

This morning I've done the reordering of the best practice according to proposal 5 on the wiki[1]. I also removed the BPs that were to be deleted.

So, the document now has its new structure. Still to be done:
- Two BPs that have been split off from what was BP8 (geometries) and BP14 (linking spatial data) need new titles and the actual splitting of the text has to be done.
- Introduction sections in chapter 12 need to be looked at - in some cases some text should be added and in others probably shortened. I didn't delete any of the introductory material, just reordered it along with the BPs themselves.

I will have more time to work on the intro sections on Monday; but others can now continue work based on the reordered version.

This closes ACTION-310 [2].

[1]: https://www.w3.org/2015/spatial/wiki/BP_2017_reordering_proposal
[2]: https://www.w3.org/2015/spatial/track/actions/310

Linda