Use a more elegant way to use libarchive from base. Instead of removing
the check in configure.ac, hint it with the right flags. That way we
can avoid patching configure.ac [1]

[1] Submitted by: kwm


git-svn-id: svn://creme-brulee.marcuscom.com/ports/trunk@20007 df743ca5-7f9a-e211-a948-0013205c9059