fixed bug with random calls

fixed bug with random calls

There also seemed to be a bug with the shuffling of opening positions; I had changed the declaration of the position number from long long int to u64 to comply with MSVC, but this suppressed shuffling completely. I now changed it to int. I recently noted a problem with true randomizing anyway: this was based on srand(time()), but time() apparently did not change fast enough, so that starting several games in rapid succession (because the book line contained a 3-fold repetition) produced identical games. So I now seed the random once and for all during startup, based on the msec of the time mark, and removed the other calls to srand().