Added ability to flush process output streams

src/dorkbox/executor/DeferredProcessResult.kt

@@ -475,6 +475,13 @@ class DeferredProcessResult internal constructor(private val process: Process,
         process.outputStream.flush()
     }
 
+    /**
+     * Flushes the output stream to the process.
+     */
+    fun flush() {
+        process.outputStream.flush()
+    }
+
     /**
      * Cancel waiting for this process to complete
      *