Allow testnet solo mining with no sync
Removed pandacoin specific block chain validation check
Changed default BLOCK version to 3.

POW blocks MUST always be version 2 or less to be accepted in netcoin
1.2 wallets.  POS blocks must be version 3 or higher to enable serialize
logic to handle their extra fields. POS blocks are a hard fork from 1.2
wallets.
Fix mining: need to use GetPoWHash function for POW block work
validation
Make fails. use chmod +x src/leveldb/build_detect_platform