New function "ordeig" (patch #9670) * scripts/linear-algebra/ordeig.m: New file. * scripts/linear-algebra/module.mk: Add new file. * scripts/help/__unimplemented__.m: Remove ordeig from the list. * libinterp/corefcn/schur.cc, libinterp/corefcn/ordschur.cc, libinterp/corefcn/qz.cc: Mention ordeig in the documentation. * NEWS: Mention the new function. Thanks to Marco Caliari who did most of the work. review and push by Andreas Weber <andy.weber.aw@gmail.com>

--- a/NEWS	Thu Aug 02 16:19:11 2018 -0700
+++ b/NEWS	Fri Aug 03 16:22:33 2018 +0200
@@ -35,6 +35,10 @@
     when using OpenGL graphics, the Qt QOFFSCREENSURFACE feature must be
     available and you must use the qt graphics toolkit.
 
+ ** New functions added in 5.0:
+
+      ordeig
+
  ** Deprecated functions.
 
     The following functions have been deprecated in Octave 5.0 and will