Don't use separate variable for number of trinkets in level

Same principle as removing the separate variable to track number of
collected trinkets. This means it's less error-prone as we're no longer
tracking number of trinkets separately.

In the function that counts the number of trinkets, I would've liked to
have used std::count_if(). However, the most optimal way would require
using a lambda, and lambdas are too new for the C++ standard we're
using. So I just bit the bullet and counted them manually.

desktop_version/src/editor.h

@@ -151,7 +151,7 @@ class editorclass{
   std::vector <int> swapmap;
   std::vector <int> contents;
   std::vector <int> vmult;
-  int numtrinkets;
+  int numtrinkets();
   int numcrewmates;
   edlevelclass level[400]; //Maxwidth*maxheight
   int kludgewarpdir[400]; //Also maxwidth*maxheight