[BusyBox] read_gz patch

[Laurence Anderson]

When I was adapting my rpm applet and had to fork to uncompress the cpio 
archive, which I based on get_header_tar_gz I noticed that for bzip2 archives 
you didn't have to, due to the read_bz2 method. Just out of interest I wrote 
a similar thing for gzip too, so there is no need to fork on unzipping 
archives. However there's a catch - its slower as it copies the data twice 
(but then a pipe does that) and i've seen it use about 400k memory on highly 
compressed files (like the kernel source).

Anyway, its at 
http://www.warwick.ac.uk/~esvld/programming/patches/busybox/busybox-read_gz.diff

I dunno what people think, is it useful? The main thing it that it removes the 
need to fork.

Laurence