This makes it possible to call tweeper.php with an absolute path.
For now the stylesheet are assumed to be in the same directory of the
program; I have no experience with distributing php software for command
line usage, so I don't know yet how to properly handle include paths.
if (FALSE === $url || empty($url["host"]))
die("Invalid url: $url\n");
-$stylesheet = "rss_converter_" . $url["host"] . ".xsl";
+$stylesheet = __DIR__ . "/rss_converter_" . $url["host"] . ".xsl";
if (FALSE === file_exists($stylesheet))
die("Conversion to RSS not supported: {$url["host"]}\n");