Add styles for upower and sndio.

Index: resources/style.css
--- resources/style.css.orig
+++ resources/style.css
@@ -164,6 +164,21 @@ button:hover {
     color: #000000;
 }
 
+#upower {
+    background-color: #2980b9;
+    color: #fff;
+}
+
+#upower.discharging {
+    background-color: #2980b9;
+    color: #fff;
+}
+
+#upower.charging {
+    background-color: #288049;
+    color: #fff;
+}
+
 label:focus {
     background-color: #000000;
 }
@@ -199,6 +214,16 @@ label:focus {
 }
 
 #pulseaudio.muted {
+    background-color: #90b1b1;
+    color: #2a5c45;
+}
+
+#sndio {
+    background-color: #f1c40f;
+    color: #000;
+}
+
+#sndio.muted {
     background-color: #90b1b1;
     color: #2a5c45;
 }
