It's now possible to order by associated models. This technically might
have worked before b/c we were parsing JSON sent to `order`, but I'm
pretty sure it wouldn't actually work b/c we never grabbed the actual
model to associate by. Regardless, this actually enables things and adds
tests to prove it.
Note: there's a sequelize bug that's poorly reported but definitely
known where `order` with associated models can fail because the sql
generated doesn't include a join. So, I added docs noting that and a
`test.failing` so that we'll be notified when that bug is fixed and can
remove the note.
Previously, {one,many}-to-many relationships with models would result in
`associationNames` that were plural. e.g. `Team` might have many
players and one location. The validation was expecting to see the plural
`Players` and the singular `Location` but Sequelize is expecting the
singular `Player` (`Location` worked fine). This meant that include
lookups would silently fail. This fixes the problem in a backward-
compatible way.
It continues to allow `include=Location` (capitalized) for backward-
compatibility. And now allows and actually does the lookup for
`include=players`, `include=player`, `include=Player`, `include=Players`
lookup relationships.
AFAIK, hapi-sequelize doesn't have a `request.models`, but it does have
a `request.getDb()` method that has `models` on it. This calls that
method to get the related models, but allows `request.models` to keep
working for backward compatibility.
