* Fix encrypted memo decryption
* from_account and to_account in Memo() can also be a publick and private key
* Prepare for sbd/steem replacement by hbd/hive
* Add unit test for beem.memo

* new beemstorage module
* Config is handled by SqliteConfigurationStore or InRamConfigurationStore
* Keys are handled by SqliteEncryptedKeyStore or InRamPlainKeyStore
* Move aes to beemgraphenebase
* Wallet.keys, Wallet.keyStorage, Wallet.token and Wallet.keyMap has been removed
* Wallet.store has now the Key Interface that handles key management
* Token handling has been removed from Wallet
* Token storage has been move from wallet to SteemConnect/HiveSigner

* decryption of long messages fixed
* varint decoding added to memo decryption

* Message class improved
* beempy message can be used to sign and to verify a message

* add Prefix class for PasswordKey, Brainkey, Address, PublicKey, PrivateKey, Base58
* New Class BitcoinAddress
* Address class has now from_pubkey class method

* Fix update_account_jsonmetadata and add posting_json_metadata property to Account
* Add Ledger Nano S support
* beempy -u activates ledger signing
* beempy -u listkeys shows pubkey from ledger
* beempy -u listaccounts searches for accounts that have pubkey derived from attached ledger
* beempy -u keygen creates pubkey lists that can be used for newaccount and changekeys
* new option use_ledger and path for Hive

add path parameter to beempy keygen

More unit tests have been added

* Add hive node
* update_account function added to blockchaininstance
* normalize added to PasswordKey, so that a Brainkey can be set as PasswordKey
* Fixed vote percentage calculation when post rshares is negative
* new beempy command changekeys
* beempy keygen can be used to generate account keys from a given password and is able to generate new passwords

* Rshares, vote percentage and SBD/HBD calculation has been fixed for votes
* post_rshares parameter added to all vote calculations

Rename SteemWebsocket to NodeWebsocket and SteemNodeRPC to NodeRPC

* steem object in all classes is replaced by blockchain
* Hive and Steem are now BlockChainInstance classes
* Each class has now blockchain_instance parameter (steem_instance is stil available)
* shared_blockchain_instance and set_shared_blockchain_instance can be used for Hive() and Steem() instances
* token_symbol, backed_token_symbol and vest_token_symbol

* Add get_blockchain_name to Steem, returns either steem or hive
* Add switch_blockchain to Steem, can be used to switch between hive and steem
* Storage has now a new config "default_chain", can be either hive or steem
* updatenode --hive switches to hive and use hive nodes
* updatenode --steem switches to steem and use steem nodes