ACPI power usage displayed incorrectly on some machines

[Arjan van de Ven]

bluebird wrote:
> Hi,
> 
> As you probably didn't know the "present rate"
> in /proc/acpi/battery/*/state can be in Watt or Ampere(depends on your
> hardware). PowerTop is assuming it is Watt so if your battery uses
> Ampere it shows something like 0.9 W as power usage(Would be great!)

yeah I saw that this morning in the mails

> 
> PS: Hope the code isn't too bad


it looks quite good actually; I'll merge it and then change it around 
a bit; I think it's possible to simplify it even more a little

thank you for the contribution!