RFR: JDK-8141333 Rename SetupArchive to SetupJarArchive

[Magnus Ihse Bursie]

It is not very clear that SetupArchive is actually creating a jar file. 
Analogous with SetupZipArchive, it should be renamed to SetupJarArchive. 
Also, the implementation should be moved to a separate file, out of 
JavaCompilation.gmk.

Bug: https://bugs.openjdk.java.net/browse/JDK-8141333
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8141333-fix-SetupJarArchive/webrev.01

/Magnus