[DEBUG] Remote node initial peer_state receipt key err

 - At remote node (destination from on-demand node), the first
  peer_state info from TinCan can happen to make error.

 - Also, there was a bug in trimming policy.
Merge pull request #13 from kyuhojeong/master

[DEBUG] Remote node initial peer_state receipt key err
[DEBUG] Fail tracking traffic statistic after node destroyed
[DEBUG] removes commented codes
Merge pull request #14 from kyuhojeong/debug

[DEBUG] Fail to tracking traffic statistics after connection destroyed
Disconnection synchronization

When we destroy transport connection, we simply remove uid-map in
tincan. Potentially, if one node destroy connection, the remote
node still can consider the connection exists leading to unexpected
behaviros such as forwarding packet to disconnected node or
destroying connection right after the connection is re-established
when previous connection is destroyed in a near past.
Correcting typo
Putting spaces around addition operator and correct key in dic

 - put spaces around addtiion operator
 - Also, there was mistake on key in the self.state dictionary
Merge pull request #15 from kyuhojeong/sync_dc

Disconnection synchronization