Bug#4063: magicfilter has wrong path

[branderh@iaehv.nl (Erick Branderhorst)]

> 2. There is another problem with extracting the filter from the set of
>    filters in /usr/doc/examples/magicfilter/filters/filters.tar.gz as the 
>    extracted file is not registered with dpkg --- upon removal of the package
>    a useless file will remain on the machine.

a if [ "$1" = "purge" ] ; then  in postrm should remove these filters IMHO.
I suggested this unpacking of filter because these filters take up quit some
space and they are never used.
 

> 4. The package suggests pbmplus, and we don't seem to have such a package. I
>    think that netpbm replaced pbmplus.

I'm sure on this.

Erick