Allow archive to decompress splitted files

Which part would be affected

The decompressor bundled inside archive.src

Description of the feature

It should parse archName.tar.part1, archName.tar.part2... as one huge archName.tar

How would it enhance the experience?

It would allow to install "virtual archives" bigger than GH's character limit

Checks to do

• Can still decompress existing files
• Compress files the same way as before
• Splitted archives work as intended