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.