Patch for Solaris/Illumos

Tested with OpenIndiana a151a9 and other patches for current master of corosync and pacemaker.
All 9 tests passes without error.
See here:
https://lists.fedorahosted.org/pipermail/quarterback-devel/2013-April/thread.html#1016

The changes solve this problems:
- If the file already exists when we try to bind the same address, the bind request will fail. When we close the socket, this file is not automatically removed, so we need to make sure that we unlink it.
- If a peer disconnects ECONNRESET or EPIPE is returned and must be replaced with ENOTCONN
- The global signalhandler must be resetted to the default