allow ouch to decompress archive into existing folder

[a-moreira]

closes #296

[figsoda]

This doesn't ask recursively for files in subdirectories, but this also seems to the default behavior as mentioned in the original comment

[marcospb19]

This doesn't ask recursively for files in subdirectories, but this also seems to the default behavior as mentioned in the original comment

From my tests it seems that it is asking recursively, however, there are some surprises when using --dir and triggering the smart unpack functionality.

With --dir the output is redirected to another folder, but if you're unpacking an archive with more than one file inside, it will unpack it inside of an extra nested folder.

I think you thought it was not asking to overwrite because it was unpacked on another folder, so no paths conflicted.

This is probably talk for another issue or PR, smart unpack should probably be disabled when --dir is present (or even completely removed from Ouch).

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Thanks @a-moreira for your PR! 🎉 🎉 🎉

[marcospb19]

@a-moreira I forgot to tell you to add an entry to CHANGELOG.md, I'll be making a commit with your name in there.

EDIT: #324.