night theme: add workaround for grayscale filter not working on firefox, other minor tweaks

themes/night.css

@@ -3,12 +3,17 @@
 body#ttrssMain #feeds-holder {
 	background : #222;
   	border-color : #666;
+	border-left-width : 1px;
 }
 
 body#ttrssMain #headlines-frame {
 	border-color : #ddd;
 }
 
+body#ttrssMain div.whiteBox {
+	border-color : #666;
+}
+
 body#ttrssMain #content-insert {
 	background : #333;
 }
@@ -132,6 +137,7 @@ body#ttrssMain #feedTree img,
 body#ttrssMain .postContent img {
 	filter: grayscale(1);
 	-webkit-filter: grayscale(1);
+	filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); // firefox lol
 }
 
 body#ttrssMain .hl img.hlScorePic {