this, we only need some simple logic in java-env.mk to automatically
generate an ALTERNATIVES file for us.
There are two exceptions, though: fastjar and jikes (pointed out by tv@),
which do not use this file; they have to be handled manually.
Bump PKGREVISION for all affected packages.
While doing this, remove the java-wrapper package, obsoleted by the new
functionality provided by pkg_alternatives.
