test_lightningd.py: catch unexpected reconnections.

I had a weird failure which was caused by an unexpected disconnect and
reconnecct.  Since we are prersistend and recover from these, they can
slip through our tests; most tests don't involve reconnection, so we
need to catch this explicitly.

For the connect() helper, we always suppress reconnection; tests which
want it all want other options so don't use this helper anyway.  (Actually,
after I said that, test_closing_while_disconnected was added when I
rebased, which did require it, so I had to open-code that one).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/utils.py

@@ -299,12 +299,13 @@ class LightningD(TailableProc):
 
 
 class LightningNode(object):
-    def __init__(self, daemon, rpc, btc, executor, may_fail=False):
+    def __init__(self, daemon, rpc, btc, executor, may_fail=False, may_reconnect=False):
         self.rpc = rpc
         self.daemon = daemon
         self.bitcoin = btc
         self.executor = executor
         self.may_fail = may_fail
+        self.may_reconnect = may_reconnect
 
     # Use batch if you're doing more than one async.
     def connect(self, remote_node, capacity, async=False):