RFR 15: 8243010: Test support: Customizable Hex Printer

[Roger Riggs]

Please review[2] and comment on a new Hex printing utility to support 
OpenJDK tests.
The usefulness of a hex printing has been discussed from time to time with
many suggestions as to the API shape and features.

To get an idea of the API and features, take a look at the javadoc[1].
It covers the basic formatting of offset, and values, and extends the
descriptive part beyond simple ASCII or printable so that a custom formatter
can interpret the byte stream in parallel to the bytes.

The webrev includes changes to existing tests that currently
use HexDumpEncoder to use HexPrinter.

Comments appreciated, Roger

[1]Javadoc:
http://cr.openjdk.java.net/~rriggs/webrev-hexprinter-8243010/javadoc

[2] Webrev:
   http://cr.openjdk.java.net/~rriggs/webrev-hexprinter-8243010/

[3] Issue:
   https://bugs.openjdk.java.net/browse/JDK-8243010