Fix license headers, clarify licensing on OmegaT stubs
Switch from bmsi.util.Diff to java-diff-utils
Don't do unnecessary character diffing
Allow external localized resources
Make string bundle keys all caps
Use param for dist/lib
Bundle java-diff-utils with for-OmegaT JAR
Adjust string resources for OmegaT
Warn when supplied ResourceBundle doesn't have string
Add prefix to string labels to ease embedding in other programs