Added an example to the custom_json section for documentation.

Add get_vote_pct_for_SBD, sbd_to_vote_pct and sbd_to_rshares

This calculates the vote percentage needed for having a given vote value.

Adds the possibility of calculating the needed voting weight for an account with a specified amount of SP/vests

It was slightly unclear that one of the two required auths were needed since both also say optional. Added a note explaining the need for one of the two as well as a block of pseudocode to display the message further.

new_vote flag for vote value calculations

remove auto_clean from streaming

Fix vests_to_rshares (issue #66)

* steemd.pevo.science and steemd.steemgigs.org removed from Nodelist
* bug fixed in allow and disallow for CLI
* fix #64
* Show results for get_user_data and get_feature_flags in Conveyor

fix Account.get_tags_used_by_author on appbase

Fix Blockchain.get_transaction_hex() on appbase

Refs #64

Fixes #62