Nearly all binary searches and mergesorts are broken

For details, see this blogpost from Google research: https://research.googleblog.com/2006/06/extra-extra-read-all-about-it-nearly.html

I have corrected the C implementation that is used to show Mergesort on Wikipedia, https://en.wikipedia.org/wiki/Merge_sort, but there are many more out there. Help spread the word!

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