Rename min/max intensity into iwMin/Max

* virtualize methods for overriding
Restore Escape/Return key shortcuts
Fix warnings
Fix default window level
Remove unused callbacks
Merge branch 'update-image-editor'

* update-image-editor:
  Remove unused callbacks
  Fix default window level
  Fix warnings
  Restore Escape/Return key shortcuts
  Rename min/max intensity into iwMin/Max