[CMake] Volunteering to become maintainer of FindLibLZMA.cmake

[Rolf Eike Beer]

> Hi Eike,
>
> here a new version with the version support

Looks good. Just a small nitpicks:

-you should document also the LIBLZMA_VERSION_{MAJOR,MINOR,PATCH} variables

-I would move setting LIBLZMA_LIBRARIES and LIBLZMA_INCLUDE_DIRS below the
call to FPHSA and wrap it in an "if (LIBLZMA_FOUND)"

Eike