Log Message:
Adjust apache-ant wrapper to honour JAVA_HOME

Still use the pkgsrc ${PREFIX}/bin/java wrapper by default, but
allow overriding with either of JAVACMD or JAVA_HOME.  The latter
is particularly important for other pkgsrc packages which use ant
to build and may require a specific jdk (java-jna)

Drop setting of ANT_HOME (was in a non default branch anyway)

Bump PKGREVISION