Add simple readline-like input editing to the android shell.

Adapted from http://github.com/antirez/linenoise
diff --git a/sh/parser.c b/sh/parser.c
index 67de58e..d956375 100644
--- a/sh/parser.c
+++ b/sh/parser.c
@@ -1628,7 +1628,10 @@
 #ifdef WITH_HISTORY
 	if (!el)
 #endif
+#ifdef WITH_LINENOISE
+#else
 		out2str(getprompt(NULL));
+#endif
 }
 
 /*