Python 2 pyliblzma based decompressing wrapper for lzma/xz streams

The lzma.LZMAFile class from pyliblzma for Python 2 can only construct from file paths, but not from file-like objects which support read() or write() operation. If you have an object representing an lzma/xz stream in Python 2 and you want to decompress from it in a streamed fashion, here is an example implementation using the lzma.LZMADecompressor class also from pyliblzma.