panel style changes

- based on a patch by rudolf@palaticky.com
- having three css locations with hardcoded colors,
  what could possibly go wrong in the future. :(

https://bugzilla.gnome.org/show_bug.cgi?id=756807

gnome-shell-sass @ 8ea43c4c

-Subproject commit 63e059c9237a119bfe5bfef555060e6730263936
+Subproject commit 8ea43c4c98ea82c2f06d1e6bddaa261263f10770

extensions/window-list/classic.css

@@ -12,40 +12,39 @@
     background-gradient-start: #fff;
     background-gradient-end: #eee;
     color: #000;
+    -st-natural-width: 18.7em;
+    max-width: 18.75em;
+    color: #2e3436;
+    background-color: #eee;
     border-radius: 2px;
-    padding: 4px 6px 2px;
-    text-shadow: 0 0 transparent;
+    padding: 3px 6px 1px;
     box-shadow: inset -1px -1px 1px rgba(0,0,0,0.5);
+    text-shadow: 0 0 transparent;
   }
 
   .bottom-panel .window-button:hover > StWidget {
-    background-color: #fff;
-    background-gradient-start: #fff;
-    background-gradient-end: #fefefe;
+    background-color: #f9f9f9;
   }
 
-  .bottom-panel .window-button:active > StWidget {
+  .bottom-panel .window-button:active > StWidget,
+  .bottom-panel .window-button:focus > StWidget {
     box-shadow: inset 1px 1px 2px rgba(0,0,0,0.5);
-    background-color: #ededed;
-    background-gradient-start: #ededed;
-    background-gradient-end: #ededed;
   }
 
   .bottom-panel .window-button.focused > StWidget {
     background-color: #ddd;
-    background-color: #ddd;
-    background-gradient-end: #dedede;
-    color: white;
-    box-shadow: inset 1px 1px 2px rgba(0,0,0,0.5);
+    box-shadow: inset 1px 1px 1px rgba(0,0,0,0.5);
   }
 
   .bottom-panel .window-button.focused:hover > StWidget {
-    background-color: #b9b9b9;
-    background-gradient-end: #c0c0c0;
+    background-color: #e9e9e9;
   }
 
   .bottom-panel .window-button.minimized > StWidget {
-    color: #000;
-    box-shadow: inset -1px -1px 1px rgba(0,0,0,0.4);
+    color: #888;
+    box-shadow: inset -1px -1px 1px rgba(0,0,0,0.5);
   }
 
+  .bottom-panel .window-button.minimized > StWidget {
+    box-shadow: inset 1px 1px 1px rgba(0,0,0,0.5);
+  }