CC-3430: Live Stream: Admin should be able to kick out the source connection

- Clicking a button on UI triggers sending msg to pypo, which will lead running
'kick' command in liquidsoap.

airtime_mvc/public/css/styles.css

@@ -422,7 +422,7 @@ select {
     display:block;
 }
 
-.source-connection {
+.source-kick-button {
     border:1px solid #242424;
     color:#fff;
     min-height:14px;
@@ -432,6 +432,11 @@ select {
     float: left;
 }
 
+.source-kick-button:hover{
+	cursor:pointer;
+	background-color:#FFFFFF;
+}
+
 .line-to-switch {
 	float: right;
 	width: 10px;