[niepce] Require gtk 3.22. Update .ui files. Add window title for prefs dialog

[Hubert Figuière <hub src gnome org>]

commit 133f7bc2cf1ea596dfb058d70e2ac33fda0ec95a
Author: Hubert Figuière <hub figuiere net>
Date:   Sun May 14 22:15:39 2017 -0400

    Require gtk 3.22. Update .ui files. Add window title for prefs dialog

 configure.ac                          |    5 +++--
 src/niepce/ui/dialogs/editlabels.ui   |    2 +-
 src/niepce/ui/dialogs/importdialog.ui |    2 +-
 src/niepce/ui/dialogs/preferences.ui  |    3 ++-
 4 files changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 39cce65..152e5a8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -11,9 +11,9 @@ m4_pattern_allow([^BOOST_])
 
 dnl all the library version.
 dnl if one is harcoded elsewhere, it is a bug
-LIBGIOMM_VERSION=2.16
+LIBGIOMM_VERSION=2.32
 LIBGLIBMM_VERSION=2.32
-LIBGTKMM_VERSION=3.16
+LIBGTKMM_VERSION=3.22
 EXEMPI_VERSION=2.2.0
 SQLITE_VERSION=3.0
 GEGL_VERSION=0.3.0
@@ -133,6 +133,7 @@ dnl   -Wredundant-decls \
    -Wpointer-bool-conversion \
    -Wshadow \
    -Wsign-compare \
+   -Wsuggest-override \
    -Wunreachable-code \
    -Wunused \
    -Wwrite-strings \
diff --git a/src/niepce/ui/dialogs/editlabels.ui b/src/niepce/ui/dialogs/editlabels.ui
index 3f32f39..23d6b0f 100644
--- a/src/niepce/ui/dialogs/editlabels.ui
+++ b/src/niepce/ui/dialogs/editlabels.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.20.0 -->
 <interface>
-  <requires lib="gtk+" version="3.16"/>
+  <requires lib="gtk+" version="3.20"/>
   <object class="GtkDialog" id="editLabels">
     <property name="can_focus">False</property>
     <property name="border_width">5</property>
diff --git a/src/niepce/ui/dialogs/importdialog.ui b/src/niepce/ui/dialogs/importdialog.ui
index c8f1ab7..d19bfb1 100644
--- a/src/niepce/ui/dialogs/importdialog.ui
+++ b/src/niepce/ui/dialogs/importdialog.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.20.0 -->
 <interface>
-  <requires lib="gtk+" version="3.16"/>
+  <requires lib="gtk+" version="3.20"/>
   <object class="GtkListStore" id="import_source_model">
     <columns>
       <!-- column-name label -->
diff --git a/src/niepce/ui/dialogs/preferences.ui b/src/niepce/ui/dialogs/preferences.ui
index c79175c..88c092a 100644
--- a/src/niepce/ui/dialogs/preferences.ui
+++ b/src/niepce/ui/dialogs/preferences.ui
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- Generated with glade 3.20.0 -->
 <interface>
-  <requires lib="gtk+" version="3.16"/>
+  <requires lib="gtk+" version="3.20"/>
   <object class="GtkDialog" id="preferences">
     <property name="can_focus">False</property>
     <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | 
GDK_BUTTON_RELEASE_MASK</property>
     <property name="border_width">5</property>
+    <property name="title" translatable="yes">Preferences</property>
     <property name="window_position">center-on-parent</property>
     <property name="default_width">400</property>
     <property name="default_height">300</property>