* Now supports caching of generic async operations, with resource accounting done by explicit calls to acquire disposable objects.
* When a resource is requested that would exceed the hard limit specified in an option, cache items are purged until the resource can be satisfied.
* Items in the cache are reference counted, and will not be purged while referenced.
#jira
[CL 29563686 by ben marsh in ue5-main branch]
a7a017106a