Feature request: Add `AutoFinishLzmaWriter` for the .lzma file format

[sorairolake]

I opened a pull request that uses this crate to add lzip (de)compression to ouch (ouch-org/ouch#863). I also opened a pull request to use this crate instead of the liblzma crate for xz compression (ouch-org/ouch#865). These use AutoFinishLzipWriter and AutoFinishXzWriterMt to finish the stream writing. This is because the existing code in https://github.com/ouch-org/ouch/blob/aeb27ccfcd628056d0daffb6166e54320b2448c7/src/commands/compress.rs seemed to assume that the stream writing would be finished by the Drop trait.

ouch does not yet support the .lzma file format compression. If AutoFinishLzmaWriter is added, ouch will be able to support the .lzma file format compression. If this is implemented, I would like to add the .lzma file format compression to ouch.

[hasenbanck]

Yes, that's fine to add. But wouldn't it be better do just provide a simple wrapper struct AutoFinisher<T: AutoFinish> that calls the finish method of the writer then?

[sorairolake]

@hasenbanck

But wouldn't it be better do just provide a simple wrapper struct AutoFinisher<T: AutoFinish> that calls the finish method of the writer then?

Yes, I think that would be better. In that case, I would like to remove the existing AutoFinish* and replace it with AutoFinisher.

[hasenbanck]

In that case, I would like to remove the existing AutoFinish* and replace it with AutoFinisher.

Yeah, that's fine.