option for sort: sort human readable file sizes

[Cornelis de Gier]

du, df and ls all have an option -h or --human-readable which is very 
helpful displaying large file sizes. I didn't know of an easy way to 
sort the output of this option, so I wrote a -h option for sort. It's 
very helpful to identify large directories in a command like this:

du -h | sort -h

...
800K    /var/cache/man
924K    /var/www/icons
948K    /var/cache/yum/nluug-updates-released/headers
1.1M    /var/lib/scrollkeeper/index
...

I'm willing to share my implementation if you're interested.

Cornelis