Do not extract settings, this would overwrite the $level method argument.
Do not rely on implicit variable creation, it's discouraged and causes possible undefined variable flagging by code analysis tools.
Fix typo in class doc-block, this isn't the Coupler behavior.
Make metadata caching configurable. This gives the user more control, makes testing easier and avoids polluting the cache with test data.
Add tests covering MetaBehavior::metadata() and metadata caching.
Merge pull request #55 from ndm2/metadata-cleanup-caching-and-tests

Metadata cleanup, configurable caching and additional tests