Comment
* dpeth property added

Adding account methods for feed, blog, comments and replies

fix spelling errors reported by misspell

Snapshot
* update_in_vote added 
* enable_votes changed to enable_in_votes and enable_out_votes
* build_rep_arrays added
Example
* account_vp_over_time added
* account_reputation_by_SP added
Discussion
* check if parameter exists in discussion_query added

Scheduled weekly dependency update for week 28

discussions: allow empty replies

setting `set_next_node_on_empty_reply` for Discussions_by_feed and
Discussions_by_comments
Fixes #54

fix discussions.Replies_by_last_update()

`start_parent_author` parameter was missing in the RPC call and the
Query class.
Fixes #52

discussions: set steem inst. as keyword argument

Fixes #49

beem/steem.py: calculate with absolute used_power values

Fixes #46

Scheduled weekly dependency update for week 27

CLI
* upvote and downvote fixed
Snapshot
* refactoring
* update_vote and build_vp_arrays added for showing vote power history
Examples
* account_vp_over_time added

* Fixes issue #45 by checking the timestamp of last_payout instead of net_rshares. With these changes, voting of unvoted posts/comments is possible.
* Refactoring of Transactionbuilder and adding of _use_condenser_api for defining the use of condenser api on broadcasting when using appbase nodes.. 

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