Some optimizations concerning lapack and copying
In the current version, it is possible to replace zaxpy by zgemv called when an Ising spin is flipped which couples to more than one DoF. Also, at least the Intel compiler issues some unnecessary memcopies when if fails to analyse the consistency of the memory structure of the matrix, mostly caused by matrices passed as e.g. A(:,:,b,c) to zgemm. If the memory was allocated - as they were - this can be replaced by A(1,1,b,c) to avoid the additional temporary copies introduced by the compiler. I think this should be fixed before the release and I will provide the optimizations I have already implemented for the SPT_optimized version.