* NEW: Add Hierarchy::prepopulate_numchildren_cache()
API: Hierarchy::stageChildren() customisations must be applied to the base class and not include record-specific behaviour.
Adds the ability to prepopulate the cache for Hierarchy::numChildren()
in a batch.
Note that this optimisation means that stageChildren() is not called on
each record in order to calculate numChildren(). This means that the
structure of the stageChildren() query must be the same for all records
and the behaviour cannot be customised only for a subclass of the base
data class. For example, apply your customisations to SiteTree and not
a subclass.
This is an useful part of optimising the query count on tree generation.
See https://github.com/silverstripe/silverstripe-framework/issues/8379
* NEW: Add Hierarchy::prepopulateTreeDataCache()
This provides a more extensible way of preopulating caches for optimised
tree generation.
Fixes https://github.com/silverstripe/silverstripe-framework/issues/8391
API Substitute Zend_Locale with Locale / NumberFormatter
API Substitute Zend_Date with IntlDateFormatter
API Added DBTIme::Nice12, FormatFromSettings
API Added Short() method to DBDate / DBTime / DBDatetime
API Add Date::getTimestamp()
API Added setSubmittedValue api for FormField
API Add second arg to base FormField::setValue()
API Major refactor of i18n into component data parts
API Implement Resettable interface to reset objects between tests
ENHANCEMENT Changed DBField::create_field return type to `static` to support better type hinting
ENHANCEMENT i18nTextCollector supports __CLASS__
