Add prime.h to project file.
Set nMaxSieveSize slightly easier to configure - could also add QT mapping if desired. 

Probably makes sense for nSieveRoundOptimal as well - but I didn't have time to test.
Merge pull request #15 from joebauers/master

Primecoin: Add prime.h to qt project file
Primecoin: Set nMaxSieveSize slightly easier to configure
(joebauers)