Log Message:
Changes 4.50:
A new version of LU-factorization routines were added.
Currently this version provides the same functionality as the
old one, however, the new version allows further improving.

Old routines for FHV-factorization used to update the basis
factorization were replaced by a new version conforming to the
new version of LU-factorization.

Some clarifications about using the name index routines were
added.

Some typos were corrected in the MathProg language reference.

A serious bug (out-of-range indexing error) was *tentatively*
fixed in the routine glp_relax4. Unfortunatly, this bug is
inherited from the original Fortran version of the RELAX-IV
code (for details please see ChangeLog), and since the code is
very intricate, the bug is still under investigation.