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/photoboothdialog.cpp b/photoboothdialog.cpp
index 826144f..6a804f3 100644
--- a/photoboothdialog.cpp
+++ b/photoboothdialog.cpp
@@ -1,5 +1,5 @@
 /***************************************************************************
- * Copyright (C) 2016 by Savoir-faire Linux                                *
+ * Copyright (C) 2017 by Savoir-faire Linux                                *
  * Author: Edric Ladent Milaret <edric.ladent-milaret@savoirfairelinux.com>*
  *                                                                         *
  * This program is free software; you can redistribute it and/or modify    *