Disconnect if solo participant

[raedah]

If a client detects that their are no other participants in the join, instead of sending the transaction through the server, the client should instead disconnect and create a normal splittx locally without using the server.

[raedah]

In addition to the above safety check on the client to only go through the server if there are other participants, there should also be a min participants setting on the server. If the minimum number of participants are not connected to the server, the timer will not cause the transaction to be released and will instead wait until the minimum participants have connected.

[huyntsgs]

Fixed in above commits

[raedah]

Verified working.