Making Programs Faster

`Pod::ParseTree::append`

Will failing to agglomerate strings cause any problems?
There might be code that is depending on there not being two consecutive strings
But I don't think there is
Access to Pod::ParseTree objects is mediated by methods like this:

        sub raw_text {
           my $self = shift;
           my $text = "";
           for ( @$self ) {
              $text .= (ref $_) ? $_->raw_text : $_;
           }
           return $text;
        }

This will work fine if I change append
Let's give it a try