Include identifying version number

[mikldt]

We should make it possible to figure out which version of the player is running to help diagnose problems. This could be as simple as a file somehwere.

This could optionally be reported back to the server via bandshell.

We should also create git tags with each new release to help trace files back to the code. A good resolution to this would be a release handbook (or automated script) which includes both updating the version internally and tagging the release.

[augustf]

Well, the 0.9.x numbering scheme is more or less of my invention. But in this case, what are we showing and tagging? The bandshell release, the player build? What if someone does a gem update on bandshell? Do we just show the version of each?