[Unit Testing] Disable tests depending on config.
[Detail] Minor renaming for convenience.
[Detail] Functional decomposition.

At last, I've refactored very similar entities - opening a record in usual (base) logger and in Verbose one. Previously Verbose logger delegated opening a record after doing primary filtering, but it wasn't cheap. Now there isn't delegation, but there is composition and code reuse.

Moreover, this commit makes possible to squish filters in Verbose and Base loggers into the same entity. Also using combined lightweight view provides more faster filtering, but there are a lot of work left.
[Documentation] Minor fixes.
[Detail] More forward declarations.
[API] Filtering function review.

Logging filtering function now accepts lightweight combined attribute set view. Technically it allows to perform faster filtering, because there is no need to construct combined set - it will be constructed only if the filtering succeed.
[Code Style] Minor.