Apply fix #42 and #41 from https://github.com/xeroc/python-bitshares

 * 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

More unit tests added
Some bug fixes