New Events class, Cleanup for legacylogger, monolog 

**Converting preload to events**
Preloads are an event handling system, but limited by both a misleading name, and the inability to dynamically register a new event listener. This change takes care of both issues. Full backward compatibility is mantained for now.

- Xoops\Core\Events takes over for XoopsPreload
- Xoops\Core\PreloadItem takes over for XoopsPreloadItem
- Xoops::getInstance()->events() takes over for ->preload()

- modules/(name)/preloads/*.php processing is unchaged (that is the 'preload' part.)
- New  method addListener('event.name',callable) to register listeners on the fly

*also*
Hopeful fix for issue with legacylogger
Fix issue with monolog