Refactor EditDistance, EditDistanceDouble, LongestCommonSubsequenceDistance hierarchy

[cicirello]

Summary

Within the package org.cicirelo.sequences.distance, the classes EditDistance, EditDistanceDouble, LongestCommonSubsequenceDistance form a hierarchy. EditDistance currently has 2 constructors, one for int valued costs and the other for double-valued costs, delegating the double-valued case to its current super class EditDistanceDouble, and with documented exceptions if one tries to use the int-valued distance methods when double values passed for the costs. This was a very strange choice to make at the time. It stemmed from some refactoring, and specific reasons are no longer clear. But regardless of the rationale at the time, it was a bad choice.

Refactor to clean this up, including removing the double-valued costs constructor of EditDistance, and removing EditDistance's dependence upon EditDistanceDouble by removing the extends.

Clean up the documentation as necessary.

This will be a breaking change.

Also, review and consider refactoring the logic of the algorithm implementation itself.