TS-973 Add elysium_channel, fix a few bugs

Added module elysium_channel, receive timeout and send timeout (none of which is used until 0.1.7).
Don't kill decayed sessions, but instead use supervisor:terminate_child / supervisor:start_child.
Changed some error logging to info logging.

After applying this pull request, tag the baseline with '0.1.6b'.
it will end up calling ets_buffer:write_dedicated() again for the same {{self(), Sid_Reply_Ref}, Start_Time}. what is the impact when session becomes available. The caller receives another another Sid (in mailbox), but not able to handle it?