Turn map.contents into a plain array

map.contents always has 1200 tiles in it, there's no reason it should be
a vector.

This is a big commit because it requires changing all the level classes
to return a pointer to an array instead of returning a vector. Which
took a while for me to figure out, but eventually I did it. I tested to
make sure and there's no problems.

desktop_version/src/Map.h

@@ -82,9 +82,9 @@ public:
     int roomdeaths[20 * 20];
     int roomdeathsfinal[20 * 20];
     static const int areamap[20 * 20];
-    std::vector <int> contents;
+    int contents[40 * 30];
     bool explored[20 * 20];
-    std::vector <int> vmult;
+    int vmult[30];
 
     int background;
     int rcol;