[0.3.7] stop trusting $find, actually connect to seeds

The $find event may have been sent before a local $drop event, meaning
that the node will reconnect to a known dead node. Then, because
masterless doesn't track the id of the node during handshake, masterless
doesn't report a disconnect from that node, and the node remains in the
set of known nodes, causing a leak.

The $spark handler was only keeping connections, but wasn't creating new
connections. TODO: that process should first check if masterless already
has a connection to said node.

Signed-off-by: Eli Skeggs <eskeggs@globesherpa.com>
Merge branch 'master' of github.com:globesherpa/solidipes