Adjust alignments of dropdown headers

Probably better.

Change-Id: Ibe9e26f2627631e174c1557f7e7176890de48127

resources/mixins.less

@@ -107,8 +107,8 @@
 // Dropdowns
 .dropdown-header() {
 	cursor: pointer;
-	margin-bottom: -1em;
+	margin-bottom: -0.45em;
-	padding-bottom: 1em;
+	padding-bottom: 0.45em;
 
 	&:after {
 		display: inline-block;

resources/screen-desktop.less

@@ -70,7 +70,7 @@ div.mw-notification-area {
 
 	// Because the overflow:hidden above messes up the alignment...
 	#personal h2:after {
-		height: 18px;
+		height: 22px;
 	}
 }
 
@@ -110,7 +110,7 @@ div.mw-notification-area {
 		font-weight: normal;
 		font-size: 1.25em;
 		background-image: url( images/user-grey.svg );
-		background-position: left 7px;
+		background-position: left 9px;
 		background-repeat: no-repeat;
 
 		.dropdown-header();