Fixed build on OSX.

- For some reason the "extern int pid_daemon" usage in libwebsockets.c would cause an "undefined symbols" linker error for the test-apps. This only happens with the CMake project, not the normal Makefiles. I have no clue why this is. Fixed it by getting the pid via a function instead.

- Added test-server-extpoll

- Renamed the library from libwebsocket -> libwebsockets
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 17fd7ef..d747166 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -1513,7 +1513,8 @@
 #endif
 
 #ifndef LWS_NO_DAEMONIZE
-	extern int pid_daemon;
+	extern int get_daemonize_pid();
+	int pid_daemon = get_daemonize_pid();
 #endif
 
 	lwsl_notice("Initial logging level %d\n", log_level);
@@ -1561,6 +1562,7 @@
 		if (wsdll)
 			poll = (PFNWSAPOLL)GetProcAddress(wsdll, "WSAPoll");
 
+		/* Finally fall back to emulated poll if all else fails */
 		if (!poll)
 			poll = emulated_poll;
 	}