issue browserifying 'topojson'

http://wzrd.in/bundle/topojson

output:

```
---FLAGRANT SYSTEM ERROR---
Error: "browserify exited with code 1"

code: 1
stderr: Error: module "topojson//github.com/fb55/cqs" not found in require()

dirPath: /tmp/topojson11384-14880-16dt212
Get ahold of @jesusabdullah on freenode, twitter or github
with the ENTIRETY of the contents of this message, and he can
try to help you out.

Have a nice day!

```

weird thing is that the string "github.com/fb55/cqs" doesn't appear in the topojson code base: https://github.com/mbostock/topojson

Start by reproducing the browserify request at http://wzrd.in/bundle/topojson and compare the reported missing module with the topojson source at https://github.com/mbostock/topojson. Trace where the unexpected github.com/fb55/cqs require is introduced; done means the topojson bundle builds without that phantom dependency.

Written by the indexing model from the issue text.