reuse CryptoPeerConnection objects instead of always creating new ones

Signed-off-by: Thomas Stilwell <stilwellt@openlabs.co>
Merge pull request #1006 from benemorius/peerconnection-reuse

reuse CryptoPeerConnection objects (too-many-files bug hotfix)
Remove msig folder.
Merge pull request #1012 from yagoulas/drop_msig

Remove msig folder.
Unit test proof-of-burn address generation.
Refactor trust.py.

* Groom imports.
* Refine logging output.
* Use Static Single Assignment in burnaddr_from_guid.
Merge pull request #1013 from Renelvon/test_trust

Initial tests and refactor of trust.py
Update donation address.
Merge pull request #1014 from Renelvon/new_donation_address

Update donation address.
Use self.transport in dht instead of passing it as parameter
Merge pull request #1015 from yagoulas/dht_light_cleanup

Use self.transport in dht instead of passing it as parameter
Remove unused handlers for messages negotiate_pubkey and response_pubkey
Remove unused respond_pubkey_if_mine from transport.py
Remove unused Cryptor field in CryptoTransportLayer
Merge pull request #1016 from yagoulas/unused_messages

Remove unused message handlers
Factor a BitMessageChat class out of CryptoTransportLayer

Conflicts:
	node/transport.py