Coincontrol cleanup (e.g. add missing license)

- add missing license headers
- make compatible with Qt5
- enforce header cleanup style
- small code style cleanups
- rename Coin Control dialog into Coin Control Address Selection
- use default font for the windows labels (no monospace)

src/qt/forms/optionsdialog.ui

@@ -369,7 +369,7 @@
           <string>Whether to show coin control features or not.</string>
          </property>
          <property name="text">
-          <string>Display coin &amp;control features (experts only!)</string>
+          <string>Display coin &amp;control features (experts only)</string>
          </property>
         </widget>
        </item>