Second version of Release Candidate for HF25.

First version candidate to create a public testnet to test HF25 features.

Release v1.24.8 (fixes for API nodes).

This version is an update for API node operators. Both the get_account_history and get_account_history_rocksdb plugins now consistently use 0-based indexing of operations. The get_block_api plugin was also rewritten to eliminate excessive mutex locking. A new api call get_block_range(starting_block_num, count) was added to support fetching multiple blocks with a single api call. It was implemented in such a way that it can read multiple blocks in a single disk IO call.

Optional upgrade for API nodes

HF 24 date moved to 06 October 2020
Fixed hived version reporting to match official tag.

- HF24 date moved to the 29. Sept 
- extended api_account_object in the database_api and condenser_api by post_voting_power data to simplify frontend integration.

Fixed typo in the list of accounts to be recovered at HF24
Accounts cleared at HF23 are right now stored persistently, to be available after node restart.

Fixes related to bug in big::vector unpack (loading from stream) leading to fail state snapshot loading.

sbd_interest_rate/sbd_exchange_rate take precedence over hdb_ equivalents for better compatibility with old nodes.

effective_comment_vote_operation extended by total_vote_weight field

Internal version changed to 1.24.0

Fixed bug in premature activation of DHF funds conversion.
HF24 time set to 08. September 2020