heads up on build changes

[Rafael Schloming <rh...@alum.mit.edu>]

Hi,

I just wanted to give everyone a heads up on a change I just committed.
This may end up impacting downstream java users as the artifact names have
changed a bit.

You can see PROTON-499 for some of the gory details, but long story short I
ended up moving around some code and flattening out the structure a little
bit. Part of the changes were necessary to fix the aforementioned build
issue, and some of the changes are simply me taking advantage of the
opportunity to do a little cleanup.

I believe the impact on artifact names is that if you were previously
depending on proton-j-impl and/or proton-api, you should now just depend on
proton-j.

Please let me know if you run into any issues with this.

Thanks,

--Rafael