tcampaign_dialog: add support for setting alignment of description text from WML

data/gui/default/window/campaign_dialog.cfg

@@ -14,6 +14,7 @@
 		vertical_placement = "center"
 		horizontal_placement = "center"
 		maximum_height = 600
+		maximum_width = 1000
 
 		[linked_group]
 			id = "icon_area"
@@ -417,6 +418,7 @@
 												vertical_alignment = "top"
 
 												[scrollbar_panel]
+													horizontal_scrollbar_mode = "never"
 
 													[definition]
 
@@ -426,14 +428,14 @@
 															[column]
 																border = "all"
 																border_size = 5
-																horizontal_alignment = "left"
+																horizontal_grow = "true"
 																vertical_alignment = "top"
 
 																[label]
 																	id = "description"
 																	definition = "default"
 
-																	characters_per_line = 66
+																	wrap = "true"
 																[/label]
 
 															[/column]

src/gui/dialogs/campaign_selection.cpp

@@ -163,6 +163,11 @@ void tcampaign_selection::pre_show(CVideo& video, twindow& window)
 
 			detail_item["label"] = campaign["description"];
 			detail_item["use_markup"] = "true";
+
+			if(!campaign["description_alignment"].empty()) {
+				detail_item["text_alignment"] = campaign["description_alignment"];
+			}
+
 			detail_page.insert(std::make_pair("description", detail_item));
 
 			detail_item["label"] = campaign["image"];