Expands configuration checks

[rogercgui]

Adds the selected database and the pre-configured link to abcd.def

// Checks whether a database has been selected
if (isset($_REQUEST['base'])) {
	$baseActual = "&base=".$_REQUEST['base'];
} else {
	$baseActual = "";
}

// Checks whether a URL is set in abcd.def 
if (isset($opac_gdef['link_logo'])) {
	$link_logo = $opac_gdef['link_logo']. $baseActual;
} else {
	$link_logo = "/" . $opac_path. $baseActual;
}