Update invader and lottie samples

Samples/assets/invader.rcss

@@ -197,6 +197,7 @@ div#title_bar span
 div#window
 {
 	width: auto;
+	height: 100%;
 	padding: 10dp 15dp;
 	
 	decorator: tiled-box(
@@ -261,9 +262,7 @@ input.submit
 
 	width: 159dp;
 	height: 33dp;
-
 	padding-top: 12dp;
-	vertical-align: -18dp;
 
 	font-size: 16dp;
 	text-align: center;

Samples/basic/lottie/data/lottie.rml

@@ -21,6 +21,7 @@
 				text-align: left;
 			}
 			lottie {
+				display: block;
 				width: 100%;
 				max-height: 100%;
 			}

Samples/invaders/data/background.rml

@@ -18,14 +18,19 @@
 				bottom-density: 20;
 			}
 
-			starfield
+			img, starfield
 			{
 				display: block;
+				position: absolute;
+				top: 0;
+				left: 0;
+			}
+			
+			starfield
+			{
+				decorator: stars;
 				width: 100%;
 				height: 100%;
-				z-index: 1;
-
-				decorator: stars;
 			}
 		</style>
 	</head>

Samples/invaders/data/game.rml

@@ -23,6 +23,7 @@
 			
 			div
 			{
+				position: relative;
 				height: 43dp;
 				padding: 12dp 0 0 72dp;
 				margin: 0 20dp;

Samples/luainvaders/data/background.rml

@@ -18,14 +18,19 @@
 				bottom-density: 20;
 			}
 
-			starfield
+			img, starfield
 			{
 				display: block;
+				position: absolute;
+				top: 0;
+				left: 0;
+			}
+			
+			starfield
+			{
+				decorator: stars;
 				width: 100%;
 				height: 100%;
-				z-index: 1;
-
-				decorator: stars;
 			}
 		</style>
 	</head>

Samples/luainvaders/data/game.rml

@@ -22,6 +22,7 @@
 
 			div
 			{
+				position: relative;
 				height: 43dp;
 				padding: 12dp 0 0 72dp;
 				margin: 0 20dp;