Primecoin: Update subversion format based on BIP 14
Primecoin: Added primeseedtn.muuttuja.org as a new testnet-only DNS seed.
Fix assertion failure in CCheckQueueControl.

The constructor of CCheckQueueControl now acquires a lock on pqueue->mutex.
This prevents one of the worker threads from waking up at the same time
(due to notify_all() having been called earlier). Previously it was possible
for a worker thread to temporarily decrement nIdle which caused
assert(pqueue->nTotal == pqueue->nIdle) to fail.

Added a new mutex controlMutex to CCheckQueue as a safeguard against two
control threads using CCheckQueueControl at the same time.
Primecoin: Optimize CBlockIndex::GetBlockWork().

Use left shifting instead of repeated bignum multiplication which is slow.

This slightly reduces the CPU load on client startup since GetBlockWork()
is called for every block stored in the index.