Add deployment of a release to GitHub

Add deployment of a release to GitHub

Add Ant tasks and macros to deploy binaries to GitHub,
using GitHub's releases.

Adds an Awk script to extract GH flavoured markdown release notes
from the release.moxie file.

Adds `ok.sh` to the repository so that it is readily available.
This is a Bourne shell GitHub API client, used to create a release
on GitHub and upload the binaries.