slick/slick — pull request #925 by szeiger (2014-07-21 12:37:00+00:00)
Title: Some Column improvements from tmp/remove-column:

- Deprecate the implicit conversion from Column[T] to Column[Option[T]].
A few unit tests and the code generator relied on this conversion for
foreign key definitions. These are made explicit now, using `.?` for
Option-lifting.

- Make primitive types pack to ConstColumn instead of Column.
A primitive value is always an execution-time constant.

- Remove the unnecessary Column subtypes Case.TypedCaseWithElse and
ParameterColumn.

- Remove the `asc` and `desc` methods from Column. The implicit
conversion to ColumnOrdered is sufficient.

- Allow any `Rep` instead of only `Column` in the tuple extension
methods `~` and `~:`.

Review by @cvogt