allow using Heap.js in a webWorker

[valette]

in a worker, the global 'window' object does not exist, whereas the 'self' global object exists in both cases

[qiao]

Thanks for the PR.

It would be great if you could instead use the Universal Module Definition, so that this library can be used by more clients.

[valette]

okay, will do that. I noticed that this module actually was written using coffeescript. Does this mean I need to submit a coffeescript patch?

[qiao]

Yes, the file that needs to be modified is src/heap.coffee instead of lib/heap.js.

After the .coffee change is done, you can run npm install -d and make to compile the .coffee into .js(Feel free to leave this step to me if you don't feel like to configure the dependencies.)

Thanks :)