Enh: Reduce duplicates by enforcing unique autofills

[ginatrapani]

If someone tries to add a maker or project with an autofill of a maker/project that already exists, Makerbase should stop things there.

On the backend, need to add a unique index on autofill_network and autofill_network_user_id.

On the front end, what should happen when a user tries to insert an existing person, say, from Twitter?

[ginatrapani]

While I work on #260, realizing that anyone can add someone from Twitter to Makerbase multiple times, create multiple makers, and fire off multiple tweets. Gonna address this first to reduce the chances of that happening.

On the front end, what should happen when a user tries to insert an existing person, say, from Twitter?

Attempting to answe my own question here: on the add maker/project form, when the user presses submit and the Twitter ID is set but already exists, redirect to the existing maker or project with the error message: "This maker already exists."

Cool?

[ginatrapani]

If the existing maker or project is archived - should the app automatically unarchive it on add?

[anildash]

I think just redirect is fine, no message. Probably less confusing that way. And yep, unarchive -- that's actually kinda slick, emphasizes how the data live on.