Overpassforge

Added

- `map_to_area` wrapper with `AsAreas` object.

Changed

- Moved `out` from `Statement` to `Set` only.

Changed

- Enforced return type on query methods.

Fixed

- Overloaded `filter` methods on derived classes of `Set`
accept string arguments.

Changed

- `OverlappingAreas` inherit from `Areas`.

Added

- Direct methods for elements retrieval within areas.
- Raw string filter expressions in set's `filter` method.

Added

- Added recursed up (relations) and down (relations) sets
(`>`, `>>`, `<`, `<<`).
- Added overlapping areas statement (*is_in*).

Added

- `Elements` class representing the `nwr` query statement (`Nodes`,
`Ways` and `Relations` are specialized child classes of `Elements`).
- Filter operations on `Union` and `Difference` derived from the
`Set` class.
- Nested unions of unions are merged into a single union when the query
is built.
- Intersection using the multiplication operator.

Fixed

- Semantically incorrect filter simplification when chaining different
types of sets.

Changed

- Removed `QueryStatement` and `BlockStatement` for a generic `Set`
for better abastraction.
- `out()` doesn't return anything.
- Renamed `Intersection` filter to `Intersect`.