[isabelle-dev] JDK / Mira

[Makarius]

This is yet another attempt to get things right, and reasonably simple.

   * The isatest account takes care to provide reasonable $JAVE_HOME via
     its shell environment (the same for SCALA_HOME, but that is less
     critical).

     This is based on the observation that JAVA_HOME is difficult to
     provide uniformly for all platforms -- the official bundle does the
     trick by packaging different jdk components just the right way.

   * Actual isatest jobs make sure that ISABELLE_JDK_HOME="$JAVA_HOME"
     within the Isabelle settings environment, either before or after
     entering it.

     See also http://isabelle.in.tum.de/repos/isabelle/rev/dd04c8173bb2
     for the traditional isatest cron jobs.

I did not touch Admin/mira.py yet, because I don't understand the 
implications.  It would also require another restart of the main mira 
server process.


 	Makarius