Function kktLdl

Solution of KKT equations by a dense LDL factorization of the 3 x 3 system. Returns a function that (1) computes the LDL factorization of [ H A' GG'*W^{-1} ] [ A 0 0 ], [ W^{-T}*GG 0 -I ] given H, Df, W, where GG = [Df; G], and (2) returns a function

(G *matrix.FloatMatrix, dims *sets.DimensionSet, A *matrix.FloatMatrix, mnl int)