Add start command to REPL API

[00vareladavid]

I figure most people issue a cd after generate when starting a new project (at least that's what makes sense to me, why would you create a project and then go do something else?). From a usability standpoint, it makes sense to provide a command to do both. Thoughts?

Note: this PR is just for reference, I don't know what your policy is and I didn't do extensive testing.

[KristofferC]

Hm, it seems a bit excessive to have a completely new command that only provides a cd. We could think about defaulting to cd into the new package but I don't think there should be a completely separate verb for it.

[00vareladavid]

Best left as an issue for later

[fredrikekre]

We could make generate Foo do an implicit activate Foo withouth cding to it. This would be similar to init (although there we create the project in pwd()).

[StefanKarpinski]

It very much seems like these could be combined somehow...

[00vareladavid]

That makes sense to me.
The workflow I was thinking of is: generate Foo followed by add Example.
My gut reaction was that the add would apply to the environment I most recently handled (which would be Foo).

#418 is also relevant, they wanted to do a generate Foo followed by import Foo. Activating the environment would also make this workflow possible.

[00vareladavid]

Actually, I though about #418 some more and the best fix for that seems to add a flag to dev. E.g. dev --generate.

generate Foo could be used if the focus is Foo.

dev --generate Foo can be used if you wish to add a dependency which does not exist yet (the focus would remain on the current environment). dev --generate Foo would not activate Foo and so the defaults would reflect the intended workflow.