ui: Show news sent with update check on start screen

* News are passed as JSON string, containing an array of news items.
* Each news item has version and content (html).
* Items can be filtered by min/max version, OS and license. The first item that fits is used.
* Items can be important, which highlights the news box.
* News are not shown if older than 5 days.

fortune cookie message = You will be financially successful in case your actions are well planned.

bin/app/data/gui/startscreen/startscreen.css

@@ -29,19 +29,38 @@
 	border-radius: 10px;
 }
 
-#recentLabel {
+#titleLabel {
 	color: black;
 	font-size: 16px;
 	font-weight: bold;
 	margin-left: 6px;
 }
 
-#versionLabel {
+#textLabel {
+	color: black;
+	font-size: 12px;
+}
+
+#boldLabel {
 	color: black;
 	font-size: 12px;
 	font-weight: bold;
 }
 
+#textField {
+	background: white;
+	border: 1px solid lightgray;
+	border-radius: 12px;
+	color: black;
+	font-size: 12px;
+	margin-top: 5px;
+	min-width: 180px;
+}
+
+#textField[important=true] {
+	border: 2px solid #007ac3;
+}
+
 #updateButton, #upgradeButton {
 	margin: 1px 0 3px;
 	text-align: left;
@@ -57,19 +76,3 @@
 	color: black;
 	text-decoration: none;
 }
-
-#licenseHeaderLabel {
-	color: black;
-	font-size: 12px;
-	font-weight: bold;
-}
-
-#licenseLabel {
-	color: black;
-	font-size: 12px;
-}
-
-#welcomeLabel {
-	color: black;
-	font-size: 12px;
-}