Perl 5.19 and SIGUSR2

I've tested Triceps with Perl version 5.19. This required fixing some expected error messages that have changed, and now the patterns accept both the old and new error messages.

But the worst part is that the Perl 5.19 was crashing on SIGUSR2. If you're interested in the details, see https://rt.perl.org/rt3//Public/Bug/Display.html?id=118929. I've worked around this issue by overriding the Perl's signal handler for SIGUSR2  in the XS code.

The method is Triceps::sigusr2_setup(), and it gets called during the Triceps module loading. Internally it translates to the C++ method Sigusr2::setup() that sets the dummy handler on the first call.

This has a consequence that you can't set a real SIGUSR2 handler in Perl any more. But it stops Perl from crashing, and there probably isn't much reason to do a custom handler of SIGUSR2 anyway.