Add a longest common subsequence comparator

[larsga]

From [email protected] on January 12, 2013 12:39:54

Might be good for comparing phone numbers, for example.

Original issue: http://code.google.com/p/duke/issues/detail?id=99

[larsga]

From [email protected] on January 25, 2013 05:41:48

Algorithm reference: http://www.algorithmist.com/index.php/Longest_Common_Subsequence

[larsga]

From [email protected] on October 23, 2013 10:15:45

Longest common subSTRING has been implemented, but longest common subsequence is actually a different comparator, so that's still not done.