Add read/write support for SpecialRoomnames

Ved now puts the special roomnames from the XML into data structures,
and writes those data structures back to XML.

As Ally fixed in TerryCavanagh/VVVVVV#1265,
it turned out the game couldn't deal with empty (or whitespace-only)
roomnames, since TinyXML's element GetText() method returns NULL if it
doesn't find a text node (or only stripped out whitespace). Luckily
this is easy for Ved to workaround by just using a <![CDATA[]]> instead
of raw text in that case, since that also counts as a text node (it's
basically just an escape). The bug just got fixed in the VVVVVV repo,
but it can't hurt to include the CDATA anyway (it's just two lines of
code and it parses the same)

[pre11]

Author: Daaaav

Source/level.lua

@@ -24,6 +24,8 @@ function Level:new()
 	o.vedmetadata = false
 	o.textboxcolors = {}
 	o.textboxcolors_order = {}
+	o.specialroomnames = {}
+	o.specialroomnames_order = {}
 
 	return o
 end

Source/vvvvvvxml.lua

@@ -544,6 +544,56 @@ function loadlevel(path)
 				end
 			end
 		end
+
+		local xspecialroomnames = xml:find_or_nil(xdata, "SpecialRoomnames")
+		if xspecialroomnames ~= nil then
+			for roomname in xml:each_child_element(xspecialroomnames) do
+				local mode = xml:get_name(roomname)
+				local attr = xml:get_attributes(roomname)
+				local rx, ry, flag = tonumber(attr.x), tonumber(attr.y), tonumber(attr.flag)
+				if rx == nil then rx = 0 end
+				if ry == nil then ry = 0 end
+				if flag == nil then flag = -1 end
+				local loop = attr.loop == "1"
+
+				local name
+				if mode == "transform" or mode == "glitch" then
+					name = {}
+					for child in xml:each_child_element(roomname, "text") do
+						table.insert(name, xml:get_text(child))
+					end
+					if mode == "transform" then
+						if #name < 1 then
+							table.insert(name, "")
+						end
+					else
+						while #name < 2 do
+							table.insert(name, "")
+						end
+					end
+				else
+					mode = "static"
+					name = xml:get_text(roomname)
+				end
+
+				if lvl.specialroomnames[ry] == nil then
+					lvl.specialroomnames[ry] = {}
+				end
+				if lvl.specialroomnames[ry][rx] == nil then
+					lvl.specialroomnames[ry][rx] = {}
+					table.insert(lvl.specialroomnames_order, {x=rx, y=ry})
+				end
+				table.insert(lvl.specialroomnames[ry][rx],
+					{
+						mode = mode,
+						flag = flag,
+						loop = loop,
+						name = name,
+						progress = 0
+					}
+				)
+			end
+		end
 	end)
 
 	if not success then
@@ -902,6 +952,49 @@ function savelevel(path, lvl, crashed, invvvvvvfolder)
 		lvl.xml:delete_each_child_element(xdata, "TextboxColours")
 	end
 
+	local any_roomname_tag = false
+	local xspecialroomnames
+	for _,room in pairs(lvl.specialroomnames_order) do
+		for k,roomname in pairs(lvl.specialroomnames[room.y][room.x]) do
+			if not any_roomname_tag then
+				-- Like <colour> above - this is the first special roomname tag!
+				xspecialroomnames = lvl.xml:find_or_add(xdata, "SpecialRoomnames")
+				lvl.xml:clear_open(xspecialroomnames)
+				any_roomname_tag = true
+			end
+			local xroomname = lvl.xml:add_element_in_last(xspecialroomnames, roomname.mode)
+			lvl.xml:set_attribute(xroomname, "x", room.x)
+			lvl.xml:set_attribute(xroomname, "y", room.y)
+			if roomname.flag ~= -1 then
+				lvl.xml:set_attribute(xroomname, "flag", roomname.flag)
+			end
+			if roomname.mode == "transform" then
+				lvl.xml:set_attribute(xroomname, "loop", roomname.loop and "1" or "0")
+			end
+			if roomname.mode == "transform" or roomname.mode == "glitch" then
+				for k2,item in pairs(roomname.name) do
+					local item_tag = lvl.xml:add_element_in_last(xroomname, "text")
+					if item:gsub(" ", "") == "" then
+						-- Workaround TinyXML gotcha with a CDATA...
+						lvl.xml:add_text_in_first(item_tag, item, true)
+					else
+						lvl.xml:set_text(item_tag, item)
+					end
+				end
+			else
+				if roomname.name:gsub(" ", "") == "" then
+					-- Workaround TinyXML gotcha with a CDATA...
+					lvl.xml:add_text_in_first(xroomname, roomname.name, true)
+				else
+					lvl.xml:set_text(xroomname, roomname.name)
+				end
+			end
+		end
+	end
+	if not any_roomname_tag then
+		lvl.xml:delete_each_child_element(xdata, "SpecialRoomnames")
+	end
+
 	-- Alright, let's save!
 	cons("Saving file...")
 	local success, iferrmsg