Adding top-level files, including changelogs, copyright notices, and .gitignore
Merge pull request #2 from genomebridge/tdanford/change-file

Adding top-level files
Moving over the adam.avdl file from adam-format.

In order to get the bdg-formats repository going, I've moved over the adam.avdl file
wholesale from the adam-format module in the main adam repo.

To avoid conflicts, I've given this repo its own pom.xml with an artifactId of 'bdg-formats',
but carrying over the same version, parent pom, etc.