Remove 'samples' folder, move them to undeaD

[dkorpel]

The folder is hard to discover, and the code samples are really old, and unidiomatic D. I don't think anyone will miss them, but I could be wrong (I might ask around in the newsgroup).

I suggest moving them to https://github.com/dlang/undeaD, I'll open a PR there if this PR gets accepted. There's also a link in std.socket to update.

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[thewilsonator]

Looks good to me. Will wait a bit for other's opinions