[PATCH] ash: add support for history buffer

[Laurent Bercot]

> BusyBox writes to .ash_history after each and every command, which we don't 
> want on e.g. mobile devices with a flash-based storage device.
> Using a buffer helps reducing the amount of erase/write cycles on the 
> storage medium

 Wouldn't mobile devices with flash-based storage be better off using an
adapted filesystem layer, such as UBI ? Patching every application to
avoid writing to the filesystem does not sound like the right way to
handle this.
 Besides, although it is a most sensible choice, there is no guarantee
at all that /tmp will be a RAM filesystem and $HOME will not.

-- 
 Laurent