[14] RFR: 8212970: TZ database in "vanguard" format support

[naoto.sato at oracle.com]

Hi,

Please review the fix to the following enhancement:

https://bugs.openjdk.java.net/browse/JDK-8212970

The proposed changeset is located at:

https://cr.openjdk.java.net/~naoto/8212970/webrev.09/

This change aims to support the "vanguard" IANA time zone data format, 
which uses the negative savings and transition time beyond a day period. 
The change basically translates those negative savings and transition 
times, such as 25:00, into the ones that the current JDK recognizes, 
then produces the data file "tzdb.dat" at the build time. At the run 
time, the data file is read and interpreted as before. This way the 
produced tzdb.dat is compatible with the prior JDK releases so that the 
TZ Updater can also distribute it as a time zone update.

I have also refactored redundant copy of ZoneRules file in the build 
directory, by dynamically importing the file under src. Thus some build 
related files are modified. I am hoping folks on the build-dev can 
review those changes.

Naoto