create internal API for model field validation
|Reported by:||ptone||Owned by:||nobody|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Not to be confused with model instance validation.
Currently a model's definition is validated by admin script commands through a function located in django/core/management/validation.py
This utility checks the sanity and integrity of various field definitions on the model, and outputs errors to stdout for display by the command.
There are useful reasons to have a programatic API to this model definition validation - including during app-loading
There may be other 3rd party uses, but the primary use case and inspiration for this ticket, is to allow this validation to occur at app loading time, rather than syncdb time