This checks if we get a topic change < 5 seconds after connection.
If that's the case, ignore it.
Also this PR makes the topic change an actual EventTopicChange.
It works worse than it could be, since message correction in XMPP
works differently compared to other messengers. XMPP replaces old
message with old ID with new message with new ID. Matterbridge
remembers only old ID, that's why you can edit a message from
XMPP to the gateway only once.
Edited messages from other networks to XMPP are handled correctly
though.
Conversations can't show inline pictures if there's anything besides URL in the message body.
Workaround this issue by sending one usual message and one message with OOB data and without message body.
The second message should not be shown in the clients without OOB support, so the user won't see the empty message.
Currently fully support mattermost,slack and discord.
Message deleted on the bridge or received from other bridges will be
deleted.
Partially support for Gitter.
Gitter bridge will delete messages received from other bridges.
But if you delete a message on gitter, this deletion will not be sent to
other bridges (this is a gitter API limitation, it doesn't propogate edits
or deletes via the API)
* Move from gcfg to toml configuration because gcfg was too restrictive
* Implemented gateway which has support multiple in and out bridges.
* Allow for bridging the same bridges, which means eg you can now bridge between multiple mattermosts.
* Support multiple gateways
