Update npm dependencies, fix browserify task

Mostly this is just so we're using the latest packages for all of our dependencies. The browserify update was a bit of work to make sure we actually do the right thing. I started to remove our lodash dependency because it doesn't do much and @sebmarkbage complained. Of note: we need to use `derequire` ourselves as it was removed from browserify.

Reviewers: @spicyj @syranide

Test Plan: build it, open example, inspect output.