* Implement _get_operation_filter and use filter operations in history and history_reverse on the https://api.hive.blog api node

* New SupportedByHivemind exception has been added

* improved get_discussions calls, fallback to condenser when tags api not available
* Fix detection when content does not exists

* 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

Comment
* Add example
Steem
* improve docu
Exception
* Add TimeoutException
GrapheneRPC
* add time_limit to implement a timeout for websocket connection
Unit test
* add test for timeout implementation

Wallet
* getKeysForAccount added
* getOwnerKeysForAccount, getActiveKeysForAccount, getPostingKeysForAccount added
beemapi
* WorkingNodeMissing is raised when no working node could be found
GrapheneRPC
* cycle([urls]) is replaced by the nodes class
Nodes
* Node handling and management of url and error_counts is performed by the nodes class
* sleep_and_check_retries is moved to the nodes class
* Websocket, steemnodrpc were adpapted to the changes
Unit tests
* new tests for the nodes class
* tests adapted for websocket and rpcutils

Account
* print_info improved (Last Vote added)
* entryId changed to start_entry_id in get_feed, get_blog_entries and get_blog
*rpc.get_account_history moved to _get_account_history
* estimate_account_op added, can be used to fastly get account op numbers from dates or block nums
* history and history_reverse uses estimate_account_op
Exception
* KeyNotFound removed
Memo
* raises MissingKeyError instead of KeyNotFound
Price
* small improvement
Steem
* __repr__ added
Transactionbuilder
* get_potential_signatures, get_transaction_hex and get_required_signatures added
* raises MissingKeyError instead of KeyNotFound
VotesObject
* __contains__, __str__ and __repr__ added
Wallet
* raises MissingKeyError instead of KeyNotFound
Witness
* __contains__, __str__ and __repr__ added to WitnessObject
Steemnoderpc
* small improvements
Operationsid
* producer_reward added
Unit tests
* new function added and tests adapted to changes

account
* set_withdraw_vesting_route added
cli
 * powerdownroute, convert and interest added
steemnoderpc
* error messages improved
* _check_api_name added
* ApiNotSupported when Api is not supported by node but exists
graphenerpc
* error messages improved
rpcutils
* error messages in sleep_and_check_retries improved
unit tests
* new function added

Comment
* Check added for empty returns
Market
* refactoring
* Checks added fro empty rpc returns
storage
* default nodes are taken from utils.get_node_list
Vote
* Check added for empty rpc calls
* Check added for Unkown key return
Exception
* UnkownKey added
Steemnoderpc
* set_next_node_on_empty_reply added, to add a check on empty returns on the next rpc call
* Refactoring
* UnkownKey exception added
Transaction
* refactoring
Unit tests
test_vote improve and check for VoteDoesNotExistsException added

account
* function for reputation to score calculation
* Doku improved
amount
* better handling of offline mode
steem
* Doku improved
transactionbuilder
* handing of appbase for tx verify and broadcast improved
utils
* node list added as function
* not needed function removed
steemnoderpc
* handling of server errors improved
objects
* Amount fixed for appbase
exception
* RPCErrorDoRetry added, when a rpc call should be retried
grapherpc
* Handling of server error 500 to 511 added
* better handling when get_config does not work
unit tests
* nodes and nodes_appbase are take from utils
* keys is used instead of wif for Steem()
* unit test for broadcast added
* unit test for appbase for verify added
* test_operations added
* test_types added

All rpc calls are handled with direct api call. Register api was a relict from bitshares.

* Wallet wipe improved
* wallet purge and purgeWallet renamed to wipe
* internal node error and Unable to acquire database lock handled
* login to websocket only if username and password is provided

rpcutils.py added
Timestamp fixed for py27
New unit tests for test_rpcutils

Bug fix for account
Block structure changed, is alwas {'block': , 'id'} now.
block function removed, Block is used now
Bug fix in comment
Discussions_by_payout removed
Several bugfixes in witness
More exception added to steemnoderpc
Unit tests for appbase nodes with parameterized added
steemnoderpc-unittest added

Account:
* add appbase calls
* Parse all amounts
Asset
* Made appbase ready
* supports different asses, diffined in chains.py
Block
* add appbase calls
blockchain
* improve get_estimated_block_num
* add threaded blocks method
Comments
* add appbase calls
Discussions
* add appbase calls
Market
* add appbase calls
Steem
* current_median_history_price -> get_current_median_history
* get_reward_fund -> get_reward_funds
* get_next_scheduled_hardfork -> get_hardfork_properties
* get_hardfork_version removed
* get_reserve_ratio added
* get_witness_schedule added
Transactionbuilder
* appbase calls added
Vote
* appbase calls added
Wallet
* appbase calls added
Witness
*appbase calls added
* WitnessesByIds removed
* LookupWitnesses -> ListWitnesses
steemnoderpc
* Uses now GrapheneRPC
* appbase property added
* get_use_appbase added
* network_version added in check
Chains
* chain for appbase added
* assets restructured
* min_version added
Graphenapi removed
Graphenesrpc removed
graphenerpc added
* supports websocket and http, authomatic switching depending on the https or wss.
* Checks the blockchain_version, if 0.19.4 -> appbase ready
* Add appbase logig
* Handing for request and websocket added
Examples
* benchmark_beem is ready for appbase
* print_appbase_calls added
* print_comments added
* watching the watchers added
Unit tests fixed

reduced dependency
this allow easier pushing to conda-forge

 * reputation added
* history improved and fixed
block:
* ops and ops_statistics added
blockchain:
* function-names improved
* ops_statistics added
blockchainobject
*json export added
Comment class added
Discussion class added
steem:
* follow and account by key api added and fixed
storage:
* more nodes added
utils
* Helpfunctions added
 vote
* blockchainobject
* refresh fixed
wallet
* purgeWallet added
Witness
* printAsTable function added
* WitnessesVotedByAccount added
* WitnessesRankedByVote added
* WitnessesByIds added
* LookupWitnesses added
Steemnoderpc
* register_apis fixed
test_wallet
* unit tests added
test_utils
* unittests added