Add log framework

v0/log.c

@@ -0,0 +1,16 @@
+#include "log.h"
+#include <stdio.h>
+
+static LogError* s_logError = NULL;
+
+void log_set_output(LogError* destination) {
+    s_logError = destination;
+}
+
+void log_error(const char* msg) {
+    if (s_logError != NULL) {
+        s_logError(msg);
+    } else {
+        fprintf(stderr, "Error: %s\n", msg);
+    }
+}