* add get_token_per_mvest

* add get_replace_hive_by_steem() to Hive(), which is True on HF23
* Replace HIVE by STEEM and SBD by HBD only when Hive HF < 24
* Replace steem and sbd paramter names for Hive HF >= 24 by hive and hbd
* Add get follow list to Account (only for HIVE and HF >= 24)

Scheduled weekly dependency update for week 25

* Retry up to 5 times when coingecko price api failes

* 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 UnknownTransaction exception that is raised when using get_transaction with an unkown trx_id
* New function is_transaction_existing which returns false, when a trx_id does not exists
* beempy info does not show information for a trx_id
* broadcast from TransactionBuilder can now return a trx_id, when set trx_id to True (default)
* sign and finalizeOp from Hive and Steem return now the trx_id in a field
* add export parameter to all broadcast commands in beempy
* When setting unsigned in beempy, the default value of expires is changed to 3600

blockchain.py: handle virtual ops batch streaming

* 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

* receiver parameter removed from beempy decrypt
* beempy encrypt / decrypt is able to encryp/derypt a binary file
* encrypt_binary, decrypt_binary and extract_decrypt_memo_data added to beem.memo
* extract_memo_data added to beembase.memo

* beempy encrypt / decrypt can be used to encrypt/decrypt a memo text with your memo key

* 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

* add participation_rate to Blockchain
* beembase.transactions is deprecated
* get_block_params added to TransactionBuilder