`sdiff` command is not implemented

[oSoMoN]

Currently uutils' diffutils only implements the diff executable.

But GNU's diffutils also provide cmp, diff3 and sdiff.

This issue is a tracker for the implementation of the sdiff utility.

Documentation: https://www.gnu.org/software/diffutils/manual/html_node/Invoking-sdiff.html.

[sami-daniel]

taking this up

[zxvfc]

Hi! I'd like to work for this issue, this issue appears to be available (last activity was nearly a year ago).

After investigating the current code I've found that the existing side_diff implementation isn't fully GNU-compatible for sdiff's requirements. I'm proposing to split the implementation into 4 phases with separate PRs:

1. Basic non-interactive implementation of sdiff, which is just reusing side_diff
2. Add sdiff specific options/flags
3. Implement interactive mode
4. Fixes

[sylvestre]

please go ahead

[sylvestre]

@sami-daniel please avoid doing that in the future :( thanks :)

[zxvfc]

Added PR: #159