Implement simple log viewer
Fix some typos in app logs
LogViewer: Make sure to display all available logs
Replace JavaScript Settings with native equivalent.

This will be required to allow native and QML code access the same
settings store at the same time.
Default cover: Add upper limit to the number of parsed thumbnails.

YouTube can return more results than specified in maxResults query
param. In such case just ignore any extra data we get.
Logger: Add categorization support for default Qt logger.