v4.5.19.1 release

v4.5.19.1 had one improvement and two bug fixes.

Significant improvement

• Improved performance of the References tab in the Content Type widget by implementing DataCache, thereby avoiding unnecessary Query and recursive reference lookups. See "Breaking changes," below.

Significant defect addressed

• Corrected an issue causing the method ByIdIterator#next to indefinitely return the same object.
• Corrected an issue causing delays of up to five minutes in cache replication.

Breaking changes

Subclasses of com.psddev.cms.type.Item need to implement ItemContainer to pick up any possible ReferenceField usages in the References tab.