* Add `getFieldMap` method to retrieve a list of all fields for any given class
* Add `TagsToShortcodeTask` to upgrading guide
Adding after the file migration part as this is where it makes the most sense to run it.
* `getFieldMap` accepts an array
* Move to `DataObjectSchema`
* Add `HTMLVarchar` to documentation
Minor refactoring
* Add test for checking that `subclassesfor` works without the base class
Add test `DataObjectSchema::getFieldMap` returns the correct array
* Remove cms dependency
* API Support many_many through polymorphic relations (from side only)
Fixes#7911Fixes#3136
* Add extra docs and allow optional arguments
* ENHANCEMENT Enable quiet to be turned off
* BUG Fix issue with manymanythroughlist duplication
API Add DataObject::setComponent()
API Support unary components as getter and setter fields
API ManyManyList::add() now supports unsaved records
ENHANCEMENT Animal farm
The $class variable gets overwritten in the function.
This causes error messages to be less helpful. For example if you setup a has_many but forget the has_one on the other side the error will look something like
`[Emergency] Uncaught Exception: No has_one found on class 'SomeObject', the has_many relation from 'SilverStripe\View\ViewableData' to 'SomeObject' requires a has_one on 'SomeObject'`
fixing this gives a more useful error, like
`[Emergency] Uncaught Exception: No has_one found on class 'SomeObject', the has_many relation from 'Page' to 'SomeObject' requires a has_one on 'SomeObject'`
