Add a new straight line option for drawing lines

[oskari]

Controlled by a prop lineStyle while still being backwards-compatible with the noCurves prop.
Maybe in a some major release we can drop the noCurves prop in favor of the lineStyle.

example:

[oskari]

I actually just noticed that this might be what PR #120 was trying to achieve, thus fulfilling issue #119

[pierpo]

... this is amazing!

Thank you so much for the contribution. I will have a deeper look, but what I've seen so far is just fantastic. The API makes totally makes sense, too!

Same as the other PR, I'll have a deeper look in the following days, then merge & publish 😊

[pierpo]

I'm really amazed that you pulled this off so easily. I thought it would be way more complex! Thank you for your help, this is amazing!

However, there are merge conflicts now that I merged your other PR. Could you resolve them? 😊

[oskari]

I'm really amazed that you pulled this off so easily. I thought it would be way more complex! Thank you for your help, this is amazing!

However, there are merge conflicts now that I merged your other PR. Could you resolve them? 😊

Can't take much credit for it. Spend few hours trying to figure out how it should be calculated when I realized that the offset calculation was already doing it, so had to just adapt it a bit.

Merge conflicts should be resolved now. I added the startMarker to eighth example as I've been using that to verify everything looks like they're supposed to do.

[pierpo]

Well, that's fantastic. Truly amazing job, thank you so much for the contribution!