Improve scoring system

[encounter]

The scoring system is currently very naive. decomp.me / asm-differ will be good references.

[ribbanya]

Would most of the work (ie, implementing Levenshtein) be as simple as importing this thing and comparing the lines as strings like asm-differ does^{[1] [2]}? Or am I missing something?

[encounter]

New scoring system based on asm-differ implemented in v3.0.0-alpha.1