Please review Meiji era tidyup

[roger riggs]

The issue 8019185: Inconsistency between JapaneseEra start dates and 
java.util.JapaneseImperialDate
Observes a minor discrepancy between the java.util.Calendar Japanese 
implementation
and the java.time JapaneseEra.

This fix aligns the start dates of the Meiji Era to avoid the inconsistency.
http://cr.openjdk.java.net/~rriggs/webrev-meiji-start-8019185/

Thanks, Roger