Change S/L/T to summary/log/tree

In yet another attempt at better usability, the cryptic S/L/T links are
changed to show their full name.

Suggested-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
diff --git a/cgit.css b/cgit.css
index 9c79c32..112dac1 100644
--- a/cgit.css
+++ b/cgit.css
@@ -371,16 +371,17 @@
 
 a.button {
 	font-size: 80%;
-	color: #333;
-	background-color: #ccc;
-	border: solid 1px #999;
+	color: #aaa;
+	background-color: #eee;
+	border: solid 1px #aaa;
 	padding: 0em 0.5em;
 	margin: 0.1em 0.25em;
 }
 
 a.button:hover {
 	text-decoration: none;
-	background-color: #eee;
+	color: #333;
+	background-color: #ccc;
 }
 
 a.primary {