Experimental support for using the client on macOS (Darwin) (#1321)

* shorter SHM names on macOS
* fix segfault on macOS when string is empty
* apple version of read exe path
* ifdef for linux specific API
* fixed test for shm and udp socket
* updated release notes

slsDetectorSoftware/src/CmdParser.cpp

@@ -27,6 +27,10 @@ void CmdParser::Parse(std::string s) {
     // taking s by value we can modify it.
     Reset();
 
+    // If the string is empty there is nothing to parse
+    if (s.empty())
+        return;
+
     // Are we looking at -h --help? avoid removing h from command starting
     // with h when combined with detector id (ex, 1-hostname)
     bool h = replace_first(&s, "--help", " ");