Use the old fork() method of tar compression support, rather than
read_bz2....
- (*uncompress)(int in, int out) seems like a more natural interface
for compression code.
- it might improve performance by seperating the work into one cpu
bound and one io bound process.
- There is extra code required to do read_[gz|bunzip] since (*uncompress)(int in,
int out) will normally be used by the standalone compression applet.
There have been problems with this method so if you see a "Short read"
error let me know.