Also, check programs that should fail using lurette instead of just
lus2lic. Indeed, some programs are only suposed to fail at runtime.

Change the main node names of prog in should_fail as it is necessary
for Lurette non-reg scheme

By redirecting the stderr of ecexe onto stdout, ecexe now terminate properly when called from lurette.

Hence, I have no more unresolved test (they are now failures) and the exec
time is now 98s (versus 217!!)

Some failures were actually due to wrong programs (mved to should_fail/semantics)

nb : the change has actually been done in lurette.

 - translate merge on bools in terms of current and ite
 - do not print the clock info in node profile in en mode

+ various fixes in lustre test files.

nb : now all tests in the should_work dir passes !!!

nb : I've transformed all the regressions I've seen into todo entries
in todo.org.

nb 2 : I did not mv the newly broken tests into the broken dirs. I'll
do that for those I do not want to fix in the short term.