Various small fixes in bridge and condenser api
Unused flag_weight column removed - fixed places where it was supposed to be computed
Fixed code that reads beneficiaries from operation
Changed error response from None to proper error in bridge.get_profile and bridge.get_post_header
Empty raw_json in hive_accounts no longer crashes API calls
condenser_api uses sum of payout and pending_payout for correct order by payout
When selecting blog posts with special start_index value (0 or -1) limit is shortened when there is not enough posts (was error which made no sense)