add fullscreen icon

Signed-off-by: Jan-Christoph Borchardt <hey@jancborchardt.net>

core/css/icons.css

@@ -195,6 +195,13 @@ img.icon-loading-small-dark, object.icon-loading-small-dark, video.icon-loading-
 	background-image: url('../img/actions/external.svg?v=1');
 }
 
+.icon-fullscreen {
+	background-image: url('../img/actions/fullscreen.svg?v=1');
+}
+.icon-fullscreen-white {
+	background-image: url('../img/actions/fullscreen-white.svg?v=1');
+}
+
 .icon-history {
 	background-image: url('../img/actions/history.svg?v=1');
 }

core/img/actions/fullscreen-white.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg xmlns="http://www.w3.org/2000/svg" height="16" width="16" version="1.1" viewBox="0 0 16 16">
+ <path d="m8 1c-0.554 0-1 0.446-1 1s0.446 1 1 1h5v5c0 0.554 0.446 1 1 1s1-0.446 1-1v-6c0-0.554-0.446-1-1-1h-6zm-6 6c-0.554 0-1 0.446-1 1v6c0 0.554 0.446 1 1 1h6c0.554 0 1-0.446 1-1s-0.446-1-1-1h-5v-5c0-0.554-0.446-1-1-1z" fill-rule="evenodd" fill="#fff"/>
+</svg>

core/img/actions/fullscreen.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg xmlns="http://www.w3.org/2000/svg" height="16" width="16" version="1.1" viewBox="0 0 16 16">
+ <path d="m8 1c-0.554 0-1 0.446-1 1s0.446 1 1 1h5v5c0 0.554 0.446 1 1 1s1-0.446 1-1v-6c0-0.554-0.446-1-1-1h-6zm-6 6c-0.554 0-1 0.446-1 1v6c0 0.554 0.446 1 1 1h6c0.554 0 1-0.446 1-1s-0.446-1-1-1h-5v-5c0-0.554-0.446-1-1-1z" fill-rule="evenodd"/>
+</svg>