Support `git clone --recursive`

[oalders]

@genehack thanks for all of your work on this module. Unless I've misunderstood, it doesn't look like I can got clone --recursive $url. Have I missed something?

[genehack]

Nope, that's not supported because nobody has yet mentioned needing to scratch that itch (the few external repos I have that use submodules I just do by hand). Happy to entertain patches or just leave this open as a feature request; I'm not sure when I might get around to this myself.

[oalders]

Thanks and understood. I don't think I currently have the bandwidth for a pull request, but I at least wanted to establish whether or not this is currently possible. Maybe submodules aren't so popular. :)

[genehack]

There's no reason it couldn't get added as a flag to the clone subcommand -- just needs somebody to rub the right amount of tuits on the code. 8^) I'll leave this issue open on the off chance a PRC participant wanders by or something...

[yanick]

I recommend turning off the lights, facing a mirror and whispering 'yenzie' 3 times... >.>