New logging framework / improvements that have been previously discussed, and have existed in a karaoke branch for some time.

1. Hierarchical logging (e.g. setting io.jenkins.blueocean.creation=DEBUG should trigger all nested logger underneath that namespace)
2. Easy configuration of logging levels
   1. In code, in some appropriate bootstrapping place
   2. Query parameters
   3. via Java -D parameter at startup (suitable for ATH perhaps)
3. Tracks line numbers correctly
4. Nice display of variables
   1. Display "raw" objects / arrays that can be expanded in developer tools
   2. Appropriately flattened for compatibility with browser console access in Selenium