Add lzip decompressor

[sorairolake]

lzip is a data compression file format which uses LZMA (not LZMA2). The lzip format specification is an Internet Draft. The standard library already implements LZMA decompressor and CRC-32, so I think it would be easy to add this file format to the standard library.

I think this file format is less popular than .xz, which uses LZMA2.

If this is accepted, I will implement this file format in the standard library (no guarantees about whether I will be able to, though).

[sorairolake]

I think there is less demand for this file format than for archive file formats which are already implemented in the standard library such as xz. So I don't think this file format is necessary for the standard library.