[threeten-dev] #263 performance of getAvailableChronologies

[roger riggs]

Please Review:

A startup time concern [1] is the initialization of all of the 
HijrahChronologies
whether they are used by an application or not.  This change delays
reading the HijrahChronology specific data until the first time it is 
needed.

Webrev:
    http://cr.openjdk.java.net/~rriggs/webrev-chrono-init-263/

Roger

[1] https://github.com/ThreeTen/threeten/issues/263