Gulp strategy

[lyzadanger]

The gulp structure for upstream fabricator is different from our usual strategy. OTOH, the way fabricator is designed, gulp is a sort of per-site/per-project situation. Core fabricator isn't gulp; it's simply referenced by gulp.

With that in mind:

• [x] Understand and deconstruct what the current gulpfile is doing
• [ ] How much of this can or should be refactored to get to a starting point for our types of projects?
• [ ] How much of this can or should be left as config-level stuff to be tackled per project?
• [ ] Can we at least, say, externalize the config without making too much of a mess?
• [ ] Are we OK with "ownership" of the gulp picture here? If we do more than a minimal amount of refactor, we won't be able to merge in upstream changes anymore.

[lyzadanger]

I'm deferring messing with the gulp setup until we have to, but we know how we like to organize gulp so we'll be fine.