RFR 8/9 8068284: Missing @throws in DateTimeFormatterBuilder.appendOffset, etc.

[Roger Riggs]

Please review corrections for editorial issues in java.time javadoc.

Webrev:
    http://cr.openjdk.java.net/~rriggs/webrev-time-editorial-8068284/

Issues:
   8062803: 'principal' should be 'principle' in java.time package 
description

   8068285: Missing @throws in DateTimeFormatterBuilder.appendInstant
   8062796: java.time.format.DateTimeFormatter error in API doc example

Thanks, Roger