Reworking structures for easy testing, read more

I was reworking bits of the containers to address issue #131, then
realized that the table's tests depended on a specific initial size. I'm
too buggered to finish it tonight, so I'll fix it tomorrow.

source/toy_stack.h

@@ -16,3 +16,20 @@ TOY_API void Toy_pushStack(Toy_Stack** stackHandle, Toy_Value value);
 TOY_API Toy_Value Toy_peekStack(Toy_Stack** stackHandle);
 TOY_API Toy_Value Toy_popStack(Toy_Stack** stackHandle);
 
+//some useful sizes, could be swapped out as needed
+#ifndef TOY_STACK_INITIAL_CAPACITY
+#define TOY_STACK_INITIAL_CAPACITY 8
+#endif
+
+#ifndef TOY_STACK_EXPANSION_RATE
+#define TOY_STACK_EXPANSION_RATE 2
+#endif
+
+#ifndef TOY_STACK_CONTRACTION_RATE
+#define TOY_STACK_CONTRACTION_RATE (1 / 4)
+#endif
+
+//prevent an infinite expansion, limited to 1MB
+#ifndef TOY_STACK_OVERFLOW
+#define TOY_STACK_OVERFLOW (1024 * 1024 / sizeof(Toy_Value))
+#endif