[isabelle-dev] isatest stability

[Makarius]

We've seen routine isatest dropouts in the past few weeks.  With 
Isabelle/d1ecb3554b25 there is some hope that it will work better again. 
There have been some actual issues with exceptions, interrupts and 
parallel evaluation on the Isabelle side.

I still have the ambitition to return to routine success of isatest runs, 
both from the isatest side and Isabelle + Poly/ML + X + Y + Z + ...

Lets see if it works out, even though I will be on a workshop at Orleans 
for the second half of next week, and on vacation for more than 2 weeks 
after that.


 	Makarius