InternalParseBeforeLinks tidy

- Add `FactboxBuilder`
- Tidy `FactboxCache` and remove dependency and inheritance

Changes include (to use `PHPUnit_Framework_TestCase`):
- `FactboxCacheTest`
- `InternalParseBeforeLinksTest`
- `OutputPageParserOutputTest`
- `SkinAfterContentTest`
Merge pull request #416 from SemanticMediaWiki/hooks-tidy

InternalParseBeforeLinks tidy