Disallow bare except clauses (W0702).
Restrict bare except clauses.

* All exceptions that are meant to be caught derive
  from Exception.
Merge pull request #764 from Renelvon/no_bare_except

No bare except clauses
Introducing sanitizer callbacks in transport layer.
Merge pull request #722 from sophron/sanitize-transport-data

Introducing sanitizer callbacks in transport layer
Create cursor object inside the with statement.
Merge pull request #767 from sophron/create-cursor-object-inside-the-with-statement

Create cursor object inside the with statement
Upgrade to pyelliptic version 1.5.5.
Merge pull request #768 from Renelvon/bump_pyelliptic

Upgrade pyelliptic to version 1.5.5.
Order imports according to PEP8.
Remove unused methods.

* Remove remove_peer, addCryptoPeer, _checkok, closed, get_guid,
  get_bitmessage_api, get_myself.
Remove unused argument from get_crypto_peer.
Dump connect_to_peers.
Merge pull request #765 from yagoulas/transport_initial_cleanup

Transport cleanup