#2 Fix signal handler

[Markus Elfring]

The functions "printf()" and "shm_unlink()" do not belong to the list of async-signal-safe functions.
See section "2.4.3 Signal Actions" from the document "2.4 Signal Concepts".
http://opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html#tag_02_04_03

I guess that a different program design will be needed for your function "aborthandler".
http://nptltracetool.cvs.sourceforge.net/nptltracetool/trace/nptl-trace/nptl-trace.c?revision=1.48&view=markup