Add support for LexStat cognate identification algorithm

[ddaspit]

LexStat is a statistical algorithm for detecting cognates. It would be good to add this as another cognate identification method. It is implemented in the LingPy library.

List, J.-M. (2012). LexStat: Automatic Detection of Cognates in Multilingual Wordlists. In Proceedings of the EACL 2012 Joint Workshop of LINGVIS & UNCLH (pp. 117–125).

[lingdoc]

Has anyone done a comparison of the methods implemented by Cog vs. LexStat/LingPy? I'm curious whether one is better at detecting cognates than the other, since I'm trying to decide which one to use.

[ddaspit]

Unfortunately, I am not aware of any comparisons between the approaches. The primary cognate identification approach that Cog implements is called the Blair method. I have always wanted to include other cognate identification methods in Cog, such as LexStat, so that users could try out different approaches. I have just never had time to do it.