add basic setup for origin destination grid

[BenSto]

please merge into master. this adds a basic od matrix grid interaction. but needs more effort to switch modes with radio button and so on. seems like we need also to prefill values, because calculation on the fly with a huge amount of points is way too slow. @kjoscha there is also a getLayer undefined Error in the JS Console which I didn't followed. But I think it's a good start to get deeper into the OD thing.

[00Bock]

:+1: bin gespannt wie das aussieht!