Minor fixes to PyPI package build procedure. Stubbed out a more pythonic API

packages/pypi/Makefile

@@ -1,9 +1,15 @@
+# generate a new wrapper *.cxx from the *.i interface file
+wrapper:
+	swig -c++ -python libzt.i
+
+# build and package a binary distribution
 bdist:
 	cd ../../; cmake -H. -Bbuild -DCMAKE_BUILD_TYPE=DEBUG
 	cd ../../; cmake --build build
 	cp ../../bin/lib/*.a .
 	python3 setup.py bdist_wheel	
 
+# upload to PyPI
 upload:
 	twine upload dist/*