The problem was that IM stoped guarded instances on shutdown,
but didn't wait for them to stop.
The fix is to wait for guarded instances to stop before exitting
from the main thread.
The idea is that Instance-monitoring thread should add itself
to Thread_registry so that it will be taken into account on shutdown.
However, Thread_registry should not signal it on shutdown in order to
not interrupt wait()/waitpid().
Add explicit Thread_info::Thread_info() and move both
initializers out of class definition, to solve link
problem on QNX
Makefile.am:
Preserve executable mode on scripts
make_binary_distribution.sh:
Copy *.imtest files
