Lazy-load library of theories

[olynch]

Right now, stdlib is pretty small. But there are a lot of generalized algebraic theories, and loading them requires running Julia code, so will impact our load time negatively. At some point, we should think about whether it's possible to lazy-load theories.

[epatters]

I was assuming that the standard lib that shipped with Gatlab would be small, and the library of theories of categorical structures would largely remain in Catlab. That would at least keep Gatlab lean and with a short load time.

But this would be nice to have regardless because Catlab is kinda slow to load.

[olynch]

Oh, that makes sense. Right now we're building an stdlib in Gatlab, but you are right that this really should be in Catlab; we'll move it over once Catlab depends on Gatlab.