Browser: Implement multi select user interface for object listings (#3730)

browser/app/less/inc/misc.less

@@ -99,4 +99,18 @@
 		content: '7 days';
 		right: 0;
 	}
+}
+
+
+.modal-aheader {
+	height: 100px;
+
+	&:before {
+		height: 0 !important;
+	}
+
+	.modal-dialog {
+		margin: 0;
+		vertical-align: top;
+	}
 }