Should the Record unapply method always return Some?

[marcgrr]

Similar to #46.

I had a courier record Foo { bar: Bar? } and I used it to write a bug:

foo match {
  case Foo(Some(bar)) => doStuff(bar)
}

The bug is that the match is not exhaustive. The scala exhaustivity checker would have caught this if Foo's generated unapply method had return type Some[Foo] instead of Option[Foo].

Unfortunately, the unapply method in the RecordClass.scala.txt template has some ways of returning None, which I had to remove in order to make this work.

I don't really understand why the catching that used to be there is necessary. Surely when you have an instance of a record, returning all of its fields should always succeed? If that's true, then the catching is not necessary.

(sorry I accidentally closed #54 and I don't know how to reopen it, so this is just a duplicate of #54)