Reece H. Dunn
1154409393
Use PropertyValueAliases for the script mapping.
The mapping of the script labels in the UCD data to ISO 15924
script tags is now done using the sc property map in the
PropertyValueAliases data.
This has the following benefits:
1. It removes the dependency on the IANA subtag registry.
2. It ensures the scripts are correct as specified in the
UCD data files.