Comment 1 for bug 1793356

Follow-up branch pushed:

http://git.evergreen-ils.org/?p=working/OpenSRF.git;a=shortlog;h=refs/heads/user/berick/lp1793356-xmpp-opensrf-message-subelement

1. I squashed and signed-off on Mike's 2 commits. The two commits can easily be untangled from the original branch, but given this makes opensrf XMPP compliant, I'm inclined not to support both attribute-passing mechanisms going forward.

This would mean sites with multiple servers that communicate via XMPP internally will have to be upgraded at the same time or they won't be able to communicate with one another.

2. Pushed a second commit with a number of small fixes, including a tiny ancient memory leak.

After applying fixes, I was able to use the system normally. I tested on Ubuntu 16.04 to confirm at was backwards-compatible with older Ejabberd versions.

Testing on Ubuntu 18.04 still needed.

I did not test the Java change and the Python libs remain unchanged. I believe both of these libs are in disrepair as it stands after the chunking/bundling changes in recent versions of OpenSRF.