added signal handler for fatal signals like SIGSEGV
that tries to write a call trace to error log
(or if that fails to stderr) before triggering
a core dump
Merge branch 'hartmut-segfault-handler' of https://github.com/hholzgra/MaxScale into hholzgra-hartmut-segfault-handler
Merge branch 'hholzgra-hartmut-segfault-handler' into release-1.0beta