[matrix] use gauss-jordan inversion from matrix-invert.c
[matrix] use gauss-jordan inversion from matrix-invert.c

iem-projects/ambix,umlaeute/ambix,iem-projects/ambix,iem-projects/ambix,umlaeute/ambix,kronihias/libambix,umlaeute/ambix,kronihias/libambix