Add LCS Based algorithm that finds similar strings.

[Ph0enixKM]

This solution uses the length finding variant of LCS algorithm. Time Complexity: O(n * m) Memory Complexity: O(min(n, m))

The solution itself is based on a lightweight library that I've created myself some time ago. I just realised that this great library exists and wanted to contribute my solutions as I see that you do not have LCS based algorithm in your arsenal.

[Ph0enixKM]

@dguo, are these changes sufficient?

[Ph0enixKM]

Thank you @maxbachmann for your time. I'll fix the code soon and resolve conflicts