fix #3261

fix #3260

fix #3244

For privacy reasons

[skip-ci]

We still split the JOINs with a key and the ones without

Using env variable directly used by the process, it’s easier than calling
sed on the configuration file before we start the process.  Also we don’t
need to start as root anymore, and it’s a lot cleaner.

This reverts commit 5d801ddc.

This reverts commit 45f7396c.

fix #3243

Limit of 100 MAM messages, if no other limit has been set by the client

Closes #3256

See merge request !9

fix #3259

We send 150 messages, then retrieve the archive. We should receive messages
from 50 to 149 only.

fix #3256

Fix a semblance of infinite and busy loop, that could occur if biboumi’s
poller is woken up multiple times while the XMPP server is not reachable.

fix #3255

This fixes permission problems when we bind a volume that is not owned by
the biboumi user.