Reworded a few things for consistency- should fix issue #13

I also added an `usage.js` example to make sure the code kept working - this undoubtedly belongs to functional tests, but let's have it here for now. README.md has also been updated to reflect the new options and also enumerate them (which would fix issue #9)

r? @tofumatt 
I guess `=== 0` is easier to _visually_ scan, but conceptually we just want to know "are there results?" not "are there exactly `0` results and are they of type `Number`?".