introduce generic function to multiply a small matrix onto a larger on
During a discussion with Florian, we saw some potential benefit to introduce the following function: ZSLMM(char side, char op, int N, int M, complex A(:,:), int P(:), complex B(:,:)) This function should multiply the (small) matrix op(A) [A; A^T; A^C] onto the subblock spezified by the indices in P(:) of the large matrix B from the left (side='L') or right (side='R'). This definitions is general enough to treat (almost) every Operator-Matrix multiplication and also provides a well defined area for optimizations/specializations.