1. Reduced memory footprint of header downloader and simplified it futher. Reduced network traffic consumption by the header downloader.
2. Reduced memory footprint of bor consensus code, by limiting the cache of heimdal spans to 128 entries.
3. New feature in sentry - nat stun mode for detecting node’s IP address using STUN protocol.
4. Various fixes for POS transition and hive tests.
5. Reduced memory footprint of using block snapshots (for Ethereum mainnet - by about 1.8 Gb) by using more compact Huffman decoding tables.
6. Fixed eth_feeHistory to be able to work with block snapshots.