[isabelle-dev] Poly/ML 5.3.0 packaging

[Makarius]

For the upcoming Isabelle release there will be a repackaged version of 
Poly/ML 5.3.0, see the current setup in
http://www4.in.tum.de/~wenzelm/test/polyml-5.3.0.tar.gz

The same is already installed at /home/polyml/polyml-5.3.0 locally.


There are two notable changes for improved performance:

   * A SHA1 implementation as shared object (by Sascha Böhme).  It is
     available from ML via the SHA1.digest function.  In the very worst
     case the whole thing may halt and catch fire, please report any
     problems you encounter on your system.

   * Some tuning of the Poly/ML runtime to shorted the (busy) wait interval
     for external processes from 100ms to 10ms.  This improves reactivity
     of the ML bash/bash_output functions, at the cost of burning a few
     extra cycles.


 	Makarius