Create changelog based on pull requests

[lalitkapoor]

I created a simple tool here https://github.com/lalitkapoor/github-changes.

To use it you can:
npm install -g github-changes

This was the command used to generate the changelog:
github-changes -o brianc -r node-postgres -d pulls -a -v

Please let me know if you need any help adding it to your deploy script. If there are any improvements you'd like to see in the script please feel free to open an issue :) Thanks!

[brianc]

Thanks @lalitkapoor, I'm going to add this to the repo and remove the NEWS file. I'll do major version release announcements in a more long-form manner on the wiki I think. They're the only ones that really require large amount of documentation since they contain breaking changes.