generate core dumps for failed unit tests on tinderboxes

[Stephan Bergmann]

Hi all tinderbox owners,

since the recipes for both CppunitTest and JunitTest on at least all 
(non-Apple) Unix platforms produce nice gdb-processed backtraces now 
when a test crashes and creates a core file, it would probably be 
beneficial to enable generation of core files on relevant tinderboxes.

The way I did that for (currently defunct) 
Linux-RHEL6-x86_64_14-with-check is with a 
~/.tinbuild/phases/<profile_name>.sh containing

   ulimit -c unlimited

Stephan