[gentoo-java] java_prepare in EAPI 2

[Petteri Räty]

Yesterday I added support for a java_prepare function to
java-util-2.eclass. This function will be automatically called by
java-pkg-2_src_prepare if it exists. java-pkg-2_src_prepare takes care
of showing bundled jars in strict mode (or later in eant if it's not
called) so it's preferred that it always gets run as the src_prepare for
java ebuilds so instead of having to call it explicitly from custom
src_prepare implementations we can just use java_prepare instead and not
have to worry about remembering to call it.

Regards,
Petteri