Missing parts from the original algorithm

[AxFaure]

Hi !

I noticed that several optimization that are present in the original implementations of the diff algorithm in this repo were not implemented in this crate. For instance dissimilar has no:

• line_mode
• half_diff
• timeout (There may be other missing features that I did not notice)

Since there is no mention of it in the Readme, I was wondering why you did not include them. Are these features you didn't have time to implement / don't think are useful or is there any issue preventing their implementation? And as a result, do you think we should consider adding them to the crate?