CachingResourceLocator lookup key doesn't take strict into account

CachingResourceLocator uses a CacheKey to store lookups for resources.

With e.g.

• b_nl.js
• b.js

When e.g. a strict resource lookup for b.js with locale "us" is performed, it will store the not-found for locale "us" under the cache key. The cache key consists of resource name, locale, style and variation. However when you search non-strict for locale "us", the resource locator should find the non-localized resource "b.js", but since a matching key for the lookup was stored for this particular resource, it will fail.