[isabelle-dev] NEWS: Improved Console/Scala plugin

[Makarius]

* Improved Console/Scala plugin: more uniform scala.Console output,
more robust treatment of threads and interrupts.

This refers to Isabelle/477cd67f963f.

I have standardized Isabelle/Scala towards scala.Console, with 
Output.writeln, Output.warning, Output.error_message using that as well. 
The Scala interpreter runs on a thread-local redirection of this, to print 
results in the jEdit/Console text window, instead of somewhere on 
stdout/stderr (which might be actually /dev/null).

Thus it is already possible to work with isabelle.Build.build to produce 
Isabelle documents in batch mode within Isabelle/jEdit, without using the 
old-fashioned "isabelle scala" TTY loop.  The latter is non-portable 
across OS platforms, and many users don't even know how to open a 
terminal.

Studying the Scala interpreter for several more hours, I did not get much 
further, though.  E.g. its completion mechanism is still unused by the 
console plugin.  These EPFL guys don't do the simplest possible 
implementation by default -- it looks a bit convoluted.


 	Makarius