Convert cmdedit into more generic line input facility
(make history and completion optional at runtime).
Use it for fdisk, as an example.
Some unrelated fixes in fdisk are also here.
diff --git a/shell/Kbuild b/shell/Kbuild
index eb0199e..9c60698 100644
--- a/shell/Kbuild
+++ b/shell/Kbuild
@@ -5,8 +5,8 @@
# Licensed under the GPL v2, see the file LICENSE in this tarball.
lib-y:=
-lib-$(CONFIG_ASH) += ash.o
-lib-$(CONFIG_HUSH) += hush.o
-lib-$(CONFIG_LASH) += lash.o
-lib-$(CONFIG_MSH) += msh.o
-lib-$(CONFIG_FEATURE_COMMAND_EDITING) += cmdedit.o
+lib-y += cmdedit.o
+lib-$(CONFIG_ASH) += ash.o
+lib-$(CONFIG_HUSH) += hush.o
+lib-$(CONFIG_LASH) += lash.o
+lib-$(CONFIG_MSH) += msh.o