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

Adapted from http://github.com/antirez/linenoise
diff --git a/sh/Android.mk b/sh/Android.mk
index 09bb6ac..f5218ed 100644
--- a/sh/Android.mk
+++ b/sh/Android.mk
@@ -13,6 +13,7 @@
 	expand.c \
 	input.c \
 	jobs.c \
+	linenoise.c \
 	main.c \
 	memalloc.c \
 	miscbltin.c \
@@ -31,7 +32,7 @@
 
 LOCAL_MODULE:= sh
 
-LOCAL_CFLAGS += -DSHELL
+LOCAL_CFLAGS += -DSHELL -DWITH_LINENOISE
 
 make_ash_files: PRIVATE_SRC_FILES := $(SRC_FILES)
 make_ash_files: PRIVATE_CFLAGS := $(LOCAL_CFLAGS)