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/editor.h

@@ -131,7 +131,7 @@ class editorclass{
   void saveconvertor();
   void reset();
   void getlin(const enum textmode mode, const std::string& prompt, std::string* ptr);
-  std::vector<int> loadlevel(int rxi, int ryi);
+  const int* loadlevel(int rxi, int ryi);
 
   void placetile(int x, int y, int t);