Add `localPathTemplate`

[creationix]

Also creates target directory if it doesn't exist.

[pfrazee]

Looking good! A few requests:

• Can we put the localPathTemplate on DatArchive instead of passing it into create? You'd set the template by attaching the function to the class object. (If you're not comfortable with that we can add a class function like DatArchive.setOptions() to do it.)
• Can you update the constructor to support the template fn?
• Can you add the sodium dep explicitly to package.json? (Any reason not to?)
• Can you document it in the readme?

Thanks!

[creationix]

Can we put the localPathTemplate on DatArchive instead of passing it into create?

Yes, but then we'll need to move some logic out of create (like where it checks for the path).

Can you add the sodium dep explicitly to package.json?

Sure thing.

Can you document it in the readme?

Yes, I just wanted to get the API stable first.

[pfrazee]

SGTM

[creationix]

Sorry, I got sidetracked by linux tasks (need to get final image to factory soon and need a rock solid OTA update mechanism) I'll get back to this later.