[OpenJDK 2D-Dev] RFR: 8035302: Eliminate dependency on sun.nio.cs from AWT and Motif code

[Phil Race]

http://javaweb.us.oracle.com/~prrace/8035302/

https://bugs.openjdk.java.net/browse/JDK-8035302

With this change, for the benefit of jigsaw, the Charset support needed 
by the font code
now uses just the public APIs. Some "utility" code was copied from 
sun.nio - some of
which could perhaps have been put in a public package by nio but since its
not I had to copy it. Also some tables were copied. The amount of
data may look large but there are already large data tables in this package.

Alternative solutions - that obsolete the need for the charsets - would 
be far
more disruptive.

There's a test included that I used to check this code was functioning 
as it used to
before the change. It is not exhaustive, but I believe sufficient.

-phil.