Change program id to "tag-$id"

[nmichaud]

This will also help with having non-tag based programs in the future

[osnr]

I don't love the tag-$id thing because I think the object should be identified with the entire page, not the AprilTag alone -- page-$id or program-$id would probably be better

[osnr]

or printed-program-$id I guess

[nmichaud]

Sure, although I'd like to be able to continue differentiating between different tag families (since they both encode numeric ids) since I use both (the standard one for small programmable objects and the other family for the dual tags). In some ways I feel like the id shouldn't even be visible to the end user.