Fix top panel being hidden during pause mode following 702cdbf0c7 / D2292 reported by Freagarach, ValihrAnt, Krinkle et al.

Remove the false misleading default.cfg z value that is always
overwritten by CGUI::Xeromyces_ReadObject, both introduced in
e21ebb37f5.
Remove multiline property since its redundant with the default C++
boolean, making the default style more agnostic of final GUI Object
classes.

Close advanced locale dialog correctly upon cancel following 86c151ebaa
/ D1684.
Don't switch the background image when closing the credits dialog
following bcf2c75513, refs #3744.

This was SVN commit r22966.

binaries/data/mods/mod/gui/common/modern/styles.xml

@@ -6,6 +6,7 @@
 	- DEFAULT STYLE: The style with the name 'default' is special, it will
 	- be called by every object before any other style is loaded.
 	==========================================
+	Note that the default z value is determined by GUI engine regardless of what is specified here.
 	-->
 	<style name="default"
 		absolute="false"
@@ -13,10 +14,8 @@
 		ghost="false"
 		hidden="false"
 		size="0 0 100% 100%"
-		z="0"
 		font="sans-14"
 		buffer_zone="5"
-		multiline="false"
 	/>
 	<style name="ModernWindow"
 		sprite="ModernWindow"

binaries/data/mods/public/gui/credits/credits.xml

@@ -31,7 +31,7 @@
 		<object type="button" style="ModernButtonRed" size="100%-200 100%-45 100%-17 100%-17" hotkey="cancel">
 			<translatableAttribute id="caption">Close</translatableAttribute>
 			<action on="Press">
-				Engine.SwitchGuiPage("page_pregame.xml");
+				Engine.PopGuiPage();
 			</action>
 		</object>
 	</object>

binaries/data/mods/public/gui/locale/locale.js

@@ -60,6 +60,9 @@ function openAdvancedMenu()
 
 function applyFromAdvancedMenu(locale)
 {
+	if (!locale)
+		return;
+
 	var languageList = Engine.GetGUIObjectByName("languageList");
 
 	var currentLocaleDictName = Engine.GetFallbackToAvailableDictLocale(locale);

binaries/data/mods/public/gui/session/session.xml

@@ -63,7 +63,7 @@
 	</object>
 
 	<!-- Pause Overlay -->
-	<object type="button" name="pauseOverlay" tooltip_style="sessionToolTip" hidden="true">
+	<object type="button" name="pauseOverlay" tooltip_style="sessionToolTip" hidden="true" z="0">
 		<object type="image" sprite="sessionOverlayBackground" ghost="true"/>
 		<object size="50%-128 40%-20 50%+128 40%+20" type="text" style="PauseText" ghost="true">
 			<translatableAttribute id="caption">Game Paused</translatableAttribute>