RFR:JDK-8148947:DateTimeFormatter pattern letter 'g'

[nadeesh tv]

Hi all,

BUG ID :   https://bugs.openjdk.java.net/browse/JDK-8148947

Webrev : http://cr.openjdk.java.net/~ntv/8148947/webrev.00/

Added new pattern letter  'g' for Modified Julian day.

Apart from that  made clarification  to JulianFields and  removed 
semicolons from  docs of DateTimeFormatterBuilder as suggested by Stephen

-- 
Thanks and Regards,
Nadeesh TV