packages now install several wrappers under ${PREFIX}/bin to run the
binaries installed under ${JAVA_HOME}/bin easily. While here, drop
the direct modification of PREFIX. Bump PKGREVISION to 1.
A ulimit datasize of 131072 (128K) is too small; crank to 262144 (256K).
(Whilst 132096 (129K) does work for simple tests, it's better to be
conservative and suggest something that should work most of the time...)
1. plain wrong (setting it to that will just cause compiles to explode in
interesting ways as that's source, not .class files)
2. Not needed as it can infer the default CLASSPATH from JAVA_HOME
