Use Unicode in translatable strings

See https://developer.gnome.org/hig/stable/typography.html

https://bugzilla.gnome.org/show_bug.cgi?id=772211

extensions/drive-menu/extension.js

@@ -103,7 +103,7 @@ const MountMenuItem = new Lang.Class({
     },
 
     _reportFailure: function(exception) {
-	let msg = _("Ejecting drive '%s' failed:").format(this.mount.get_name());
+	let msg = _("Ejecting drive “%s” failed:").format(this.mount.get_name());
 	Main.notifyError(msg, exception.message);
     },
 

extensions/example/prefs.js

@@ -42,7 +42,7 @@ const ExamplePrefsWidget = new GObject.Class({
 	// translated
 	let primaryText = _("Example aims to show how to build well behaved \
 extensions for the Shell and as such it has little functionality on its own.\n\
-Nevertheless it's possible to customize the greeting message.");
+Nevertheless it’s possible to customize the greeting message.");
 
 	this.add(new Gtk.Label({ label: primaryText,
                                  wrap: true, xalign: 0 }));

extensions/places-menu/placeDisplay.js

@@ -56,7 +56,7 @@ const PlaceInfo = new Lang.Class({
                 Gio.AppInfo.launch_default_for_uri(file.get_uri(), launchContext);
             });
         } catch(e) {
-            Main.notifyError(_("Failed to launch \"%s\"").format(this.name), e.message);
+            Main.notifyError(_("Failed to launch “%s”").format(this.name), e.message);
         }
     },
 

extensions/window-list/org.gnome.shell.extensions.window-list.gschema.xml

@@ -12,7 +12,7 @@
       <summary>When to group windows</summary>
       <description>
         Decides when to group windows from the same application on the
-        window list. Possible values are "never", "auto" and "always".
+        window list. Possible values are “never”, “auto” and “always”.
       </description>
     </key>
     <key name="show-on-all-monitors" type="b">