[git] git add to offer a wildcard extension

[MartinPacker]

When I update the docs for one of my GitHub projects (md2pptx as it happens) I generate a bunch of user_guide.* files. It's my practice to add them with the following command:

git add user_guide.*

Today autocomplete offers each file individually. In my case I have several I want to add all at once. I like the individual file prompting but I'd like autocomplete to also offer the generic user_guide.*.

[mschrage]

I like this idea a lot! To summarize: we should check to see if any of the staged files share a common prefix and then add the corresponding wildcard pattern as a suggestion?

[brendanfalk]

Another user comment

I was trying to git add a folder of changes eg:

• app/web/files/change.js
• app/web/files/otherthing.js

I wanted the autocomplete to stop at git add app/web/files, but there's no way to do this outside of breaking the autocomplete interface by typing a nonsensical character, or escaping the interface.

[QuiiBz]

Merged in #349, thanks to everyone!

[brendanfalk]

Going to reopen this. This PR uses two generators which is going to be really slow. We should do this with 1 generator.

[QuiiBz]

There are many other specs that use 2 generators, I don't think that really slow. We should benchmark this to see if it's really slow or not.

[QuiiBz]

Merged again in #358, using one generator (which is now really faster!)