* get_data is now fast
* update_rewards added
* enable_rewards added to build
* build_curation_arrays added

Snapshot
* impoved and STEEM and SBD history added
* Documentation added
* get_data, reset, build functions added

Snapshot added
* This class can be used to access old account states. At the moment, only changes in vests are tracked over time.
* example added for plotting SP over time

Steem
* last_node added and refresh of json_config data is forced on node switch