[Discuss-gnuradio] SWIG update

[Eric Blossom]

I'm please to announce that CVS HEAD now builds and works great with
SWIG 1.3.23 and 1.3.24 (current and current-1).

This required a change in how we build our extension modules.
If you're tracking CVS, you'll need to update and rebuild everything.

In addition, dependency tracking is now working for all the .i files
that go into the gnuradio-core swig library.

As a result of all of this, the lowest version of SWIG that we work
with is 1.3.23.  We were requiring 1.3.22.  Sorry about that, but they
made a non-compatible change in how they were handling dependencies.

Eric