Turn obj.collect and obj.customcollect into plain arrays

Since they're always fixed-size, there's no need for them to be vectors.

Also added an INBOUNDS_ARR() macro to do bounds checks with plain
arrays.

desktop_version/src/Entity.h

@@ -183,8 +183,8 @@ public:
 
     std::vector<blockclass> blocks;
     bool flags[100];
-    std::vector<bool> collect;
-    std::vector<bool> customcollect;
+    bool collect[100];
+    bool customcollect[100];
 
     bool skipblocks, skipdirblocks;