Allow selection of font for content language

* One more dropdown for content language( if it differs from UI
  language )
* Save the font preferences for both ui and content language
* many refactoring, variable renaming for this change
* Marked many TODOs and FIXMEs

Change-Id: I93ae5eced5938667af186be51bc8a5b5cd1d7eaf

resources/css/ext.uls.displaysettings.css

@@ -15,4 +15,21 @@
 
 .uls-ui-languages button#uls-more-languages {
 	width: auto;
+}
+
+.uls-content-fonts,.uls-ui-fonts {
+	padding-top: 10px;
+}
+
+.uls-content-fonts:hover,.uls-ui-fonts:hover {
+	background-color: #F6F6F6;
+}
+
+.uls-font-label strong {
+	color: #252525;
+}
+
+.uls-font-label {
+	color: #555555;
+	font-size: 10pt;
 }