'make install' after 'make' modifies source tree

[Thomas-ah-users]

With mailman 2.1.2 './configure' and 'make' run fine,
but then I switched to the mailman user account to do
'make install'.

It tried to unpack misc/email-2.5.1.tar.gz,
misc/JapaneseCodecs-1.4.9.tar.gz and
misc/KoreanCodecs-2.0.5.tar.gz, but this failed because
the mailman user doesn't have write permission in the
source tree.

I think 'make install' shouldn't need to write to the
source tree after 'make' was done. Either this has to
be done during 'make' or to the /tmp directory.

[http://sourceforge.net/tracker/index.php?func=detail&aid=784700&group_id=103&atid=100103]

[Barry Warsaw (barry)]

Fixed by addition of a make variable PKGDIR