Primecoin v0.1.2 High Performance build 10

Print the initial nRoundSievePercentage setting.

Primecoin v0.1.2 release

 - Performance improvements of built-in miner
 - chainsperday estimate in getmininginfo
 - listprimerecords command

Rename 'gensieveroundpercentage' to 'roundsievepercentage' for simpli…

…city.

Port Sunny King's fix for miner performance issue with large block size

Primecoin: Fix miner performance issue with large block size
           Miner create new block at most once every 10 seconds

Optimize GetNextCandidateMultiplier() a bit further.

Move CSieveOfEratosthenes::ProcessMultiplier to prime.h so that it ge…

…ts inlined.

Updated the README files.

Added a command line parameter -sievesize for changing the sieve size.

Restored sieve size to 1,000,000. Some quick runs on the testnet indi…

…cate that this produces a lot more probable prime chains. Thanks to the numerous people who pointed this out.