Consider using setuptools to install Python extension modules

[baagaard-usgs]

The Python extension modules are currently installed via autotools while the pure Python code is installed via setuptools. This can lead to them being installed under different directories, e.g., lib and lib64. We have attempted to mitigate this by installed the extension modules under $pkgpythondir rather than $pkgpyexecdir.

For consistency of installation, it would probably be better to install both the pure Python code and Python extension modules via setuptools. We use SWIG, so it may not be simple to setup.