add tip to pref-filters page

modules/pref-filters.php

@@ -308,6 +308,10 @@
 
 			print "<p id=\"filterOpToolbar\">";
 
+			print "<div class=\"insensitive\" style=\"float : right\">
+				First matching filter is used, filtering is performed
+				when importing articles from the feed.</div>";
+
 			print "
 					Selection:
 				<input type=\"submit\" class=\"button\" disabled=\"true\"

tt-rss.css

@@ -597,7 +597,7 @@ table.innerLoginForm td {
 	padding : 3px 3px 5px 3px;
 }
 
-span.insensitive {
+span.insensitive, div.insensitive {
 	color : gray;
 }