Ensure that all member attributes are initialized

I ran the game through cppcheck and it spat out a bunch of member
attributes that weren't being initialized. So I initialized them.

In the previous version of this commit, I added constructors to
GraphicsResources, otherlevelclass, labclass, warpclass, and finalclass,
but flibit says this changes the code flow enough that it's risky to
merge before 2.4, so I got rid of those constructors, too.

desktop_version/src/Map.cpp

@@ -76,6 +76,21 @@ mapclass::mapclass()
 	ypos = 0;
 	oldypos = 0;
 	bypos = 0;
+
+	background = 0;
+	cameramode = 0;
+	cameraseek = 0;
+	minitowermode = false;
+	scrolldir = 0;
+	check = 0;
+	cmode = 0;
+	towercol = 0;
+	tdrawback = false;
+	bscroll = 0;
+	roomtexton = false;
+	kludge_bypos = 0;
+	kludge_colstate = 0;
+	kludge_scrolldir = 0;
 }
 
 //Areamap starts at 100,100 and extends 20x20