refs #755, mapping UI improvements

* make drop area more obvious by icon and color
* improve forms so the layout looks better on large screens
* button to display model dialog (like distributor, ICAO, ...)

src/blackgui/labelandicon.ui

@@ -2,14 +2,6 @@
 <ui version="4.0">
  <class>CLabelAndIcon</class>
  <widget class="QFrame" name="CLabelAndIcon">
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>50</width>
-    <height>15</height>
-   </rect>
-  </property>
   <property name="windowTitle">
    <string>Frame</string>
   </property>
@@ -52,6 +44,19 @@
      </property>
     </widget>
    </item>
+   <item>
+    <spacer name="hs_LabelAndAction">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>40</width>
+       <height>20</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
   </layout>
  </widget>
  <resources/>