This is being done to avoid any API-breaking changes in the future. If the values are set explicitly, added values either need to force a major version update or get added as the next-highest values.
This change looks dramatic, but it's just separating out the already-split namespaces into separate top-level folders. In theory, every single one could be built into their own Nuget package. `SabreTools.IO.Meta` builds the normal Nuget package that is used by all other projects and includes all namespaces. `SabreTools.IO` builds to `SabreTools.IO.Common` to avoid overwriting issues on publish.
