* Add validation to part units field
* Add "pack_units" field to the SupplierPart model
* Migrate old units to new units, and remove old field
* Table fix
* Fixture fix
* Update migration
* Improve "hook" for loading custom unit database
* Display part units column in part table
- Also allow ordering by part units
- Allow filtering to show parts which have defined units
* Adds data migration for converting units to valid values
* Add "pack_units_native" field to company.SupplierPart model
* Clean pack units when saving a SupplierPart
- Convert to native part units
- Handle empty units value
- Add unit tests
* Add background function to rebuild supplier parts when a part is saved
- Required to ensure that the "pack_size_native" is up to date
* Template updates
* Sort by native units first
* Bump API version
* Rename "pack_units" to "pack_quantity"
* Update migration file
- Allow reverse migration
* Fix for currency migration
- Handle case where no currencies are provided
- Handle case where base currency is not in provided options
* Adds unit test for data migration
* Add unit test for part.units data migration
- Check that units fields are updated correctly
* Add some extra "default units"
- each / piece
- dozen / hundred / thousand
- Add unit testing also
* Update references to "pack_size"
- Replace with "pack_quantity" or "pack_quantity_native" as appropriate
* Improvements based on unit testing
* catch error
* Docs updates
* Fixes for pricing tests
* Update unit tests for part migrations · 1b6b6d9d
* Bug fix for conversion code
* javascript updates
* JS formatting fix
