Add date and PID to default stderr logger

When using Apache or docker, the default Std logger does not write a
timestamp.

This format (poorly) imitates the error_log format so that LLNG messages
will stand out a little less in apache logs. And so that our docker
users can have timestamped messages

lemonldap-ng-common/lib/Lemonldap/NG/Common/Logger/Std.pm

@@ -10,7 +10,7 @@ sub new {
     my $show = 1;
     foreach (qw(error warn notice info debug)) {
         if ($show) {
-            eval qq'sub $_ {print STDERR "[$_] \$_[1]\n"}';
+            eval qq'sub $_ {print STDERR "[".localtime."] [LLNG:\$\$] [$_] \$_[1]\n"}';
         }
         else {
             eval qq'sub $_ {1}';