ask npm for install prefix

[meonkeys]

This should fix #1.

Lots of whitespace changed because I indented a long switch block. This diff is short if you ignore whitespace changes.

[awatson1978]

Ooooo.... This look great. Thanks so much! Have you run through the test script and is everything working? I'm tempted to merge this in, and let it sit for a few days before publishing to npm.

[meonkeys]

Cool!

Test script? No, I just ran bin/starrynight.js stand-alone and made sure it could find npm's prefix.

Is there an easy way to test everything?

[awatson1978]

:)
That should probably be sufficient.

Right now, the walkthrough in the Examples section on http://starrynight.meteor.com is working as a test script. Need to automate it; but for the time being its better than nothing. Will want to run through that script before publishing to npm.

[meonkeys]

Ah, gotcha. I used sudo npm link to globally install from my clone's working dir, then I was able to test this version of starrynight.

Already found one issue walking through the script. I'll file it.