Get ready for 0.1.0 release to bpkg.

 - Use consistent, non-deprecated function declarations.
 - Add a package.json.
 - Use one array to pass args to gradle.
Install to /usr/local/bin by default.

+ a bit of script clean up.
Run gradle if we can't find a buildfile.
Update README for bpkg.

 - Craft a better intro.
 - Tell people how to install right away.
 - Format to 80 chars.
 - Reword a few things and clean up examples.
Merge pull request #11 from dougborg/bpkg

Add support for bpkg.