Feos

- Python only: Release the changes introduced in `feos-core` 0.6.1.

Added
- Added `EquationOfState.ideal_gas()` to initialize an equation of state that only consists of an ideal gas contribution. [204](https://github.com/feos-org/feos/pull/204)
- Added `PureRecord`, `SegmentRecord`, `Identifier`, and `IdentifierOption` to `feos.ideal_gas`. [205](https://github.com/feos-org/feos/pull/205)
- Added implementation of the Joback ideal gas model that was previously part of `feos-core`. [204](https://github.com/feos-org/feos/pull/204)
- Added an implementation of the ideal gas heat capacity based on DIPPR equations. [204](https://github.com/feos-org/feos/pull/204)
- Added re-exports for the members of `feos-core` and `feos-dft` in the new modules `feos::core` and `feos::dft`. [212](https://github.com/feos-org/feos/pull/212)

Changed
- Split `feos.ideal_gas` into `feos.joback` and `feos.dippr`. [204](https://github.com/feos-org/feos/pull/204)

- Python only: Release the changes introduced in `feos-core` 0.5.1.

Added
- Added `IdealGasModel` enum that collects all implementors of the `IdealGas` trait. [158](https://github.com/feos-org/feos/pull/158)
- Added `feos.ideal_gas` module in Python from which (currently) `Joback` and `JobackParameters` are available. [158](https://github.com/feos-org/feos/pull/158)
- Added binary association parameters to PC-SAFT. [167](https://github.com/feos-org/feos/pull/167)
- Added derive for `EntropyScaling` for SAFT-VRQ Mie to `ResidualModel` and adjusted parameter initialization. [179](https://github.com/feos-org/feos/pull/179)

Changed
- Changed the internal implementation of the association contribution to accomodate more general association schemes. [150](https://github.com/feos-org/feos/pull/150)
- To comply with the new association implementation, the default values of `na` and `nb` are now `0` rather than `1`. Parameter files have been adapted accordingly. [150](https://github.com/feos-org/feos/pull/150)
- Added the possibility to specify a pure component correction parameter `phi` for the heterosegmented gc PC-SAFT equation of state. [157](https://github.com/feos-org/feos/pull/157)
- Adjusted all models' implementation of the `Parameter` trait which now requires `Result`s in some methods. [161](https://github.com/feos-org/feos/pull/161)
- Renamed `EosVariant` to `ResidualModel`. [158](https://github.com/feos-org/feos/pull/158)
- Added methods to add an ideal gas contribution to an initialized equation of state object in Python. [158](https://github.com/feos-org/feos/pull/158)
- Moved `molar_weight` impls to `Residual` due to removal of `MolarWeight` trait. [177](https://github.com/feos-org/feos/pull/158)

Packaging
- Updated `quantity` dependency to 0.7.
- Updated `num-dual` dependency to 0.8. [137](https://github.com/feos-org/feos/pull/137)
- Updated `numpy` and `PyO3` dependencies to 0.20.

- Python only: Release the changes introduced in `feos-core` 0.4.2.

- Python only: Release the changes introduced in `feos-core` 0.4.1 and `feos-dft` 0.4.1.