Rearranged the project to have src/ and build/ directories

This simplifies keeping everything clean.

src/util.c

@@ -0,0 +1,61 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <malloc.h>
+#include <unistd.h>
+
+#include "util.h"
+
+static pthread_t main_thread;
+
+void error_init()
+{
+	main_thread = pthread_self();
+}
+
+void error(int consult_errno, int close_socket, pthread_mutex_t* unlock, const char* format, ...)
+{
+	va_list argptr;
+	
+	fprintf(stderr, "*** ");
+	
+	va_start(argptr, format);
+	vfprintf(stderr, format, argptr);
+	va_end(argptr);
+	
+	if (consult_errno) {
+		fprintf(stderr, " (errno=%d, %s)", errno, strerror(errno));
+	}
+	
+	if (close_socket)
+		close(close_socket);
+	
+	if (unlock)
+		pthread_mutex_unlock(unlock);
+	
+	fprintf(stderr, "\n");
+	
+	if (pthread_equal(pthread_self(), main_thread))
+		exit(1);
+	else
+		pthread_exit((void*) 1);
+}
+
+void* xrealloc(void* ptr, size_t size)
+{
+	void* p = realloc(ptr, size);
+	if (p == NULL)
+		SERVER_ERROR("couldn't xrealloc %d bytes", size);
+	return p;
+}
+
+void* xmalloc(size_t size)
+{
+	void* p = xrealloc(NULL, size);
+	memset(p, 0, size);
+	return p;
+}
+