Parallelized version with main and core routine.
1) Contains a trap such that for unix systems no parallel computation is done, for the moment. 2) _core routine uses and stores independent seeds for each chain; 3) Seeds for each chain are stored in record. 4) when no parallel option is chosen, usual serial functionality is kept. git-svn-id: https://www.dynare.org/svn/dynare/trunk@2676 ac1d8469-bf42-47a9-8791-bf33cf982152