RFR: JDK-8241310 Fix warnings in jdk buildtools

[Magnus Ihse Bursie]

The buildtools (java tools needed to be run during the build) have long 
been plagued by warnings, includuing deprecations and unchecked 
warnings, which cannot be silenced during the build.

This patch fixes all buildtool warnings. Most of the warnings are fixed 
properly, but a few have had their warnings suppressed locally.

For two tools, cldrconverter and tzdb, I gave up to get them fully 
fixed, and instead suppressed warnings in some places. Common for both 
these tools were that they used collections of some kind, with a mixed 
bag of data types (e.g. a Map from String to either String, HashMap, 
ArrayList and String[]). I'm frankly not sure how this could ever have 
worked :-) but I assume that the data files being parsed has a structure 
that "guarantees" that this works.

Two files in generatecharacter were missing a proper copyright header. I 
noticed this when I were about to update the copyright year, and when I 
checked the other files I noted another one without header. While I did 
not need to change this file, I thought it was suitable to fix the 
missing header for both files.

I have verified that the code generated by the build is identical with 
and without this patch.

Bug: https://bugs.openjdk.java.net/browse/JDK-8241310
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8241310-fix-warnings-in-buildtools/webrev.01

/Magnus