javaexec-script: Remove support for 'jview'. * build-aux/javaexec.sh.in: Don't test HAVE_JVIEW. * m4/javaexec.m4 (gt_JAVAEXEC): Don't set HAVE_JVIEW. Don't set CONF_JAVA to 'jview'. (gt_JAVAEXEC_DISABLED): Don't set HAVE_JVIEW. * m4/javacomp.m4: Update comment.