I've hit a few problems using zstd from an early version (0.01?) - compressed files created by the original tools were not de-compressible using more recent pro

I've hit a few problems using zstd from an early version (0.01?) - compressed files created by the original tools were not de-compressible using more recent programs :( I think the problem lies in the perl library Compress::Zstandard, rather than in the zstd code itself. The C code has flags to enable 'legacy' support and they they are on by default. The perl library doesn't seem to be using them... When I get the time, hopefully I can track this down further and submit a patch if this turns out to be the case.