Add experimental Python bindings

This commit adds some experimental Python bindings. These likely need some
further refinement in the building/deployment area, but should serve as a
useful testbed for experimentation and interactive analysis of filters and
the library's behaviour.

python/README

@@ -0,0 +1,25 @@
+Experimental Python bindings
+============================
+
+These bindings are currently experimental, as it is not yet clear how best
+to create and maintain them. They are built upon the C++ interface as the
+object oriented nature of it sits much better with Python.
+
+At present, it is necessary to compile and install the C++ library before
+working with the bindings.
+
+To generate the bindings, swig 3.0.2 has been used, but earlier versions
+may work too:
+
+  swig -c++ -python -py3 pyiir.i
+
+To build the extension, distutils is used:
+
+  python3 setup.py build_ext
+
+Note that the -L ${LIBDIR} option may be handy if libiir++ is not installed
+into the system library path.
+
+To install the extension:
+
+ python3 setup.py install