[GiNaC-list] Release 1.7.5

[Richard B. Kreckel]

Hi,

A new GiNaC version has just been released. The changes are:
* Add Markowitz-ordered Gaussian elimination.
* Avoid un-normal zeros in matrix::solve().
* Accept exprseq arguments in lsolve(eqns, vars).
* Add overload of matrix::rank(solve_algo).
* Fix case in G_do_hoelder with real x values which are not cl_R.
* Fix an elusive bug in expairseq/add ctor, introduced in 1.7.0.

Happy hacking!
  -richy.