Add command to vendor a specific system

[VisenDev]

Currently, vend get just scans your asd automatically to find the systems to vendor.

I am proposing an extension to this: vend get foo should allow you to vendor foo and all its dependencies, even if foo isn't currently used in your asd.

An additional bonus feature could be doing something like vend get https://github.com/edicl/hunchentoot which would allow your to vendor systems directly from urls

[fosskers]

I thought I had mentioned this in the README but I don't see it, and this is slightly related to your #29 .

Vend is already using git to pull dependencies, so potentially I could piggyback on all of the functionality that's already there in to accomplish this. Otherwise it's a question of "should". Seems handy for quickly adding dependency graphs that you don't want to bother editing your .asd for.

[VisenDev]

Otherwise it's a question of "should". Seems handy for quickly adding dependency graphs that you don't want to bother editing your .asd for.

The motivations I had for this feature were supporting an easy fallback when encountering problems like this #46. Or when trying to use a system that uses Package Inferred System. Or as an alternative to having a custom registry #16, instead of having a custom registry for uncommon packages that you use, you can just give vend the url to the git repo and vend will download it and its dependencies

[fosskers]

The issues with PIS would remain, as that's what prevents the proper recursive detection of further dependencies in the first place.

[VisenDev]

The issues with PIS would remain, as that's what prevents the proper recursive detection of further dependencies in the first place.

I meant that you could then manually say vend get <x> for all the dependencies of the package inferred system, and then vend could then just go from there. It provides an easy intervention