Set up automatic library distrobution with Jitpack, and move over to Gradle

[ewpratten]

This PR does a lot:

• Moved the project over to using Gradle
• Updated the examples to reflect the change (new package name)
• Updated README with new info about Jitpack
• Set up everything for Jitpack to auto-build and publish the project to https://jitpack.io/#salamander2/hsa2

[salamander2]

@ewpratten I want to look at this over the next few days and try it out. Thanks, I appreciate it.

[salamander2]

I've copied it to a new branch (gradle) in my repository and will look it over tomorrow (hopefully) to see what it does.