ATTN: maintainers of ports that use .la files at runtime

[Joshua Root]

I just merged r107527 into the release branch. If you maintain a port
that actually uses its .la files for e.g. loading plugins, you will need
to add 'destroot.delete_la_files no' to the portfile after MacPorts 2.2
is released. There shouldn't be many of these.

- Josh