code cleanup in multiple files

Last changes were merged quickly without strict code-review
as it was needed to integrate them promptly.
Related modifications:
 * callwidget.cpp: Removed unnecessary line feed
 * callwidget.{cpp,ui}: Renamed “contactRequestView” to
   “contactRequestPage” for consistency
 * contactrequestwidget.cpp: Refactoring of a too-long line
 * sendcontactrequestwidget.{cpp,ui}: Better placeholders

Moreover, contactrequestwidget.{cpp,ui} were missing the GPL
header and copyrights' years are now updated to 2017 in every
files.

Change-Id: Id52f340fc62340df6cf5bda8d782fefc732beabe
diff --git a/callwidget.ui b/callwidget.ui
index 437187e..fce54b3 100644
--- a/callwidget.ui
+++ b/callwidget.ui
@@ -1663,7 +1663,7 @@
                 </item>
                </layout>
               </widget>
-              <widget class="QWidget" name="contactRequestView">
+              <widget class="QWidget" name="contactRequestPage">
                <layout class="QVBoxLayout" name="verticalLayout_8">
                 <property name="leftMargin">
                  <number>5</number>