Significantly refactored/simplified the DistMatrix class so that each distribution is the product of a Dist, Redundant, and Cross communicator, e.g., VC x SELF x SELF for [MC,MR] and MD x SELF x MDPerp for [MD,* ]/[* ,MD], and SELF x SELF x VC for [o ,o ]. A mistake in GaussianElimination was fixed, as was a mistake in the seed calcluation for the PRNG, distributed norm calculations were generalized using the newly introduced Dist and Cross communicators, and LU with full pivoting was greatly simplified using the new RowSwap and ColumnSwap routines.