[RFC][GSOC] Microproject Suggestion

Hi, so it came to my attention that GSOC applicants will need to
submit a microproject to be considered. I was thinking about
implementing the squash as a separate feature from rebase. I did not
dig up enough in the mail history to know whether this was suggested
before or not.

It would be something that looks like this:

git squash <number_of_commits> [--offset-from-head=0]

I did not really think it through, yet, and I don't know what options
could be put there so I am open to suggestions.

My motivation is quite simple. I think it is more intuitive. When
someone first asked me to squash multiple commits before, the first
thing I had in mind was `git squash`. It was kind of a disappointment
that this was not its own command.

So does that sound like a good idea?