added input-xs class for input

SE/static/p5UI/main.css

@@ -47,3 +47,4 @@ body { <?php echo UI::fixFooterPosition('body_style'); ?> }
 
 caption { font-size:medium }
 
+.input-xs { height:22px; font-size:12px; line-height:1.2em; padding:3px 8px; }