Add option to show commit hash with -c -C

[xuningy]

I added an option for -c to show the commit hash for simpler comparison

[tessus]

Hey @xuningy . I am not sure, if this project is still maintained. None of the PRs have been merged, nor did I see any replies from the dev. If you create a PR at https://github.com/tessus/gitcheck I'll merge it....