Support protocol-relative URL:s

[jacobsvante]

I.e. without URL:s without http/https in front of them. Fixes #241.

[hirasso]

@jmagnusson, thanks for this fix! Can you tell me how to compile this into the full history.min.js file, so that I can use it?

[jacobsvante]

I've never tried buildr that they seem to use, but my guess is (from the command prompt):

1. Install Node.js
2. git clone https://github.com/browserstate/history.js.git
3. cd history.js
4. npm install
5. ./node_modules/buildr/bin/buildr

[hirasso]

Thanks! I ended up just editing the uncompressed bundled script: https://github.com/browserstate/history.js/blob/master/scripts/bundled-uncompressed/html4%2Bhtml5/jquery.history.js

I'm uglifiying it with gulp anyway.