Implement streams IPC mechanism

libaux/mprintf.c

@@ -3,6 +3,7 @@
 #include <printf.h>
 #include <process_self.h>
 #include <stdarg.h>
+#include <streams.h>
 #include <string.h>
 #include <system.h>
 
@@ -22,6 +23,6 @@ void mprintf (const char* fmt, ...) {
 
   va_end (args);
 
-  mail_send (process_get_exec_pgid (), buf, len);
+  stream_write (process_get_pgid (), STREAM_OUT, buf, len);
   free (buf);
 }