Deconstruct

This release adds a new pointer destination notation and two methods on `Struct`: `_require` and `new`.

- Struct comparison fixed so that field values are compared rather than simply field names
- Updated documentation

- Multidimensional arrays are now packed and unpacked properly
- Arrays of length 0 are now permitted
- Struct instances can now be compared

- Added support for [future annotations](https://www.python.org/dev/peps/pep-0563/)
- First release on [PyPI](https://pypi.org/project/deconstruct/)

- Added exact-width types
- Added support for multi-dimensional arrays
- Struct: made `TypeWidth.STANDARD` default
- Struct: added `to_bytes` method
- Struct: improved unpacking efficiency
- Using native-only types in a class without `TypeWidth.NATIVE` set now throws an error (previously this would only yield a generic `struct.error`)
- Empty Structs are now allowed

Initial release