Add a continue shopping url to the Donation, Product, FlatDiscount and Subscription

Sku's.  Update all the templates to display this URL.  The new url takes the
user back to the view method with no extra variables set (like hasAddedToCart).

lib/WebGUI/Help/Asset_Donation.pm

@@ -24,6 +24,7 @@ our $HELP = {
 			{	name => "hasAddedToCart" , required=>1 },
 			{	name => "thankYouMessage", description=>"thank you message help" },
 			{	name => "defaultPrice", description=>"default price help" },
+			{   name => "continueShoppingUrl" },
 			{	name => "templateId", description=>"donation template help" },
 		],
 		related => [  

lib/WebGUI/Help/Asset_FlatDiscount.pm

@@ -27,6 +27,7 @@ our $HELP = {
 			{ name => "hasAddedToCart" , required=>1 },
 			{ name => "thankYouMessage", description=>"thank you message help" },
 			{ name => "alreadyHasCoupon" },
+			{ name => "continueShoppingUrl" },
 		],
 		related => [  
 		],

lib/WebGUI/Help/Asset_Product.pm

@@ -64,6 +64,7 @@ our $HELP = {
             { 'name' => 'buy_form_footer' },
 			{ 'name' => "hasAddedToCart" , required=>1 },
 			{ 'name' => "thankYouMessage", description=>"thank you message help" },
+			{ 'name' => "continueShoppingUrl" },
             { 'name' => 'addspecification_url' },
             { 'name' => 'addspecification_label' },
             {   'name'      => 'specification_loop',

lib/WebGUI/Help/Asset_Subscription.pm

@@ -21,6 +21,7 @@ our $HELP = {
 			{	name => 'formFooter' , required=>1 },
 			{	name => 'purchaseButton' , required=>1 },
 			{	name => 'hasAddedToCart' , required=>1 },
+			{	name => 'continueShoppingUrl' },
 			{	name => 'codeControls' , required=>1 },
 			{	name => 'thankYouMessage', description=>'thank you message help' },
 			{	name => 'redeemCodeLabel' , required=>1 },