initial code removal (limited number of apparently unused code)

[carljmosca]

Issue #, if available:
#763
Description of changes:
Removed unused IonTextBufferedStream class
Removed unused boolean parameter has_sign from loadRadixValue method of IonReaderTextRawTokensX class
Removed unused private method read_utf8 from UnifiedInputStreamX class

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[tgregg]

Thanks @carljmosca, this looks good to me. One request: could you please run ./gradlew :spotlessApply and commit the resulting changes to your branch? We're migrating to a new copyright header, and any files that are touched and don't yet have the new header will cause the build to fail. Once that's done we'll merge this.

[carljmosca]

Happy to, thank you @tgregg - I appreciate your feedback and understanding. I should probably know this but should the spotless plugin be updated to the latest release? I don't have it in front of me but I think I saw another issue with the current release. TIA Carl

[tgregg]

It's been working for me as-is, but let me know if you run into issues with it.

[carljmosca]

If I move the spotless plugin from 6.11.0 to 6.25.0, the imports are corrected and the copyright is updated. Moving back to 6.11.0 (w/o changing source files) returns a java.lang.reflect.InvocationTargetException which I have not yet put time into researching.

[tgregg]

Thanks for the contribution!

[carljmosca]

Thank you @tgregg - never know with the first one but you certainly made it easy...more coming.