RFR: JDK-8034173: Move JavaApp.icns to proper place in make/data

[Erik Joelsson]

In an effort to bring some more order to the source, I have started 
moving files that are either data input for source generation, or source 
code for a gensrc tool, into a subdirectory of make instead of src. Here 
is the first patch.

In addition to moving JavaApp.icns to it's proper place in the source, I 
also change the output directory of the generated header file to 
something that more clearly indicates that it's a native header file 
rather than a java class or resource.

Bug: https://bugs.openjdk.java.net/browse/JDK-8034173
Webrev: http://cr.openjdk.java.net/~erikj/8034173/webrev.jdk.01/

/Erik