Some path computation didn't work when trying to regression test the
produced bundle.
Also, the bundle building steps would use the pgloader system definition and
dependencies from what's currently available in Quicklisp rather than from
the local pgloader.asd being built.
Now when building a bundle file for source distribution of pgloader, always
test it by building a binary image from the bundle tarball in a test
directory. Also make it easy to target "latest" Quicklisp distribution with
the following spelling:
make BUNDLEDIST=latest bundle
When distributing a pgloader bundle we're using the ql-dist facility. In
recent commit we hand-picked the last known working distribution of
quicklisp for pgloader. Make it easy to target "latest" known distribution
or hard-code one from the Makefile or the bundle/ql.lisp file.
