backports.lzma - Provides support for LXMA and XZ compressed files via
the XZ Utils C library.

This code is a backport of the Python 3.3 standard library module lzma
for use on older versions of Python where it was not included.

There are some older Python libraries like PylibLZMA and PyLZMA but
these use LZMA Utils (not XZ Utils, so they have no XZ support).
