Make the close icon configurable

src/components/misc/card.vue

@@ -6,7 +6,7 @@
 			</p>
 			<a @click="$emit('close')" class="card-header-icon" v-if="hasClose">
 				<span class="icon">
-					<icon icon="angle-right"/>
+					<icon :icon="closeIcon"/>
 				</span>
 			</a>
 		</header>
@@ -34,6 +34,10 @@ export default {
 			type: Boolean,
 			default: false,
 		},
+		closeIcon: {
+			type: String,
+			default: 'angle-right',
+		},
 		shadow: {
 			type: Boolean,
 			default: true,