Create RedirectablePrint and NoopPrint for serial debug redirection

src/RedirectablePrint.cpp

@@ -0,0 +1,13 @@
+#include "RedirectablePrint.h"
+#include <assert.h>
+
+/**
+ * A printer that doesn't go anywhere
+ */
+NoopPrint noopPrint;
+
+void RedirectablePrint::setDestination(Print *_dest)
+{
+    assert(_dest);
+    dest = _dest;
+}