Remove DETACHED_PROCESS

What DETACHED_PROCESS does is to detach the child process from the current console disallowing the passing
of TTY handles. This seems incorrect and is inconsistent with Unix. If an application actually needs to
be detached, it can use FreeConsole itself.

src/win/process.c

@@ -1103,7 +1103,7 @@ int uv_spawn(uv_loop_t* loop,
      * CreateProcess call fail if we're under job control that doesn't allow
      * breakaway.
      */
-    process_flags |= DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP;
+    process_flags |= CREATE_NEW_PROCESS_GROUP;
   }
 
   if (options->cpumask != NULL) {