[Galene] Heads up: incompatible protocol changes, Android experiment

[Juliusz Chroboczek <jch@irif.fr>]

Hi,

I've made a few protocol changes; the goal is to avoid hardwiring the
server structure in the client.

1. The handshake message now contains a version string; if the client and
   the server mismatch, you'll get a useful error message.  For now, it's
   just a warning, but it'll become a hard error in a future version.

   (This is handled for you if you use protocol.js.)

2. The group name is now derived from the status file; this means that the
   client no longer needs to parse the URL in order to determine the group
   name.

   (This is not handled by protocol.js, you need to parse .status.js yourself.)

3. The websocket endpoint is no longer hardwired in the client, it's
   published in the status file.

   (This is handled for you if you use protocol.js.)

4. The group location is now stored in the public-groups.json file,
   the client no longer needs to construct a suitable URL itself.


The reason for that: I've been frustrated with the inability to do
screenshareing on mobile, so I've been toying with a native Android
client.  If you're brave, you can find it at:

  https://galene.org/galene.apk

Sorry for the size of the file, that's because it contains four versions
of the native WebRTC library (ARM, ARM64, x86, AMD64).

-- Juliusz