Aggregation stages $unset, $project, $sort and $unionWith, sorting in find(), $concat aggregation operator ### DSL - Add the $unset aggregation stage (4be311d4, !38) - Add the $project aggregation stage (e27a6869, !38) - Add the $sort aggregation stage (8040445f, !39) - Add the $unionWith aggregation stage (d3773e41, !39) - Add the $concat aggregation operator (892491e8, !37) - Add sorting in find()'s options (c6b2acd8, !39) - Allow using the '/' notation on nullable fields (d08211e1, !39) - Improve toString of Mongo iterables (e8372cd1, !39) - Fix documentation error in the $add aggregation operator (b6db3ff2, !37) - Fix outdated Pipeline documentation (40c30ce3, !39) - Documentation improvements around aggregation pipelines (bd23fefa, !41) - Forbid nullable documents in models, as MongoDB doesn't allow them (5efad8f1, !39) ### Kotlin BSON - Various documentation improvements and clarifications (e17b899e, !41)