Non-breaking bug-fixes and improvements from @crisbour. Photon collectors now only accept photons from the direction in which they are oriented (the direction their face normal is oriented). Overlap between the ray position and the surface it is hitting is now permitted. Fixed scattering statistics and event generation ([75211f081988768c7740a1241d702ac8fd3bf498](https://github.com/aetherus-wg/Aetherus/pull/69/changes/75211f081988768c7740a1241d702ac8fd3bf498)) Switched to using an external crate (obj) for obj parsing, to speed up mesh loading. Fixed intermediate attribute linking by adopting Future. Bumped NetCDF version to support HDF5 1.14. Overhauled Nix Flake support. General improvements to formatting and Rust style conventions throughout the codebase.Photon collectors now only accept photons from the direction in which they are oriented (the direction their face normal is oriented). Overlap between the ray position and the surface it is hitting is now permitted. Fixed scattering statistics and event generation ([75211f081988768c7740a1241d702ac8fd3bf498](https://github.com/aetherus-wg/Aetherus/pull/69/changes/75211f081988768c7740a1241d702ac8fd3bf498)) Switched to using an external crate (obj) for obj parsing, to speed up mesh loading. Fixed intermediate attribute linking by adopting Future. Bumped NetCDF version to support HDF5 1.14. Overhauled Nix Flake support. General improvements to formatting and Rust style conventions throughout the codebase. Full Changelog: https://github.com/aetherus-wg/Aetherus/compare/v0.3.0...v0.3.1