Fix / Mandatory update. Qbit & Buzzer / Cubix platform

Fixed

• Difficulty calculation algo: time moving weighted average now calculates on 100 latest blocks (was 25)
• Blocks from nodes with extremely not synchronized clock will not be accepted

Deploy

1. build from sources or untar binaries
2. stop daemon
3. cd /.buzzer/0000000000000000000000000000000000000000000000000000000000000001
4. remove ltxo and utxo directories
5. start daemon with -reindex