Deprecate old URI syntax for caches
|Reported by:||FunkyBob||Owned by:||FunkyBob|
|Component:||Core (Cache system)||Version:||master|
|Has patch:||yes||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Given it was removed from the docs 3 years ago, when multi-cache support was added:
it's about time to remove it.
This cleanup will also help the work to add a thread-safe, non-duplicating cache API.