Add support for environment variables.

scripts/gen-eem.pl

@@ -37,6 +37,9 @@ foreach my $line (@contents) {
                 print OUT $line;
         } elsif ($line =~ /^!/) {
                 print OUT $line;
+	} elsif ($line =~ /^\@/) {
+		$line =~ s/^\@//;
+		print OUT $line;
         } else {
                 my $act = sprintf(" action %03d ", $action++);
                 print OUT $act . $line;