Project modernization (#630)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

Minecraft.World/BinaryHeap.cpp

@@ -58,7 +58,7 @@ Node *BinaryHeap::pop()
 {
     Node *popped = heap[0];
     heap[0] = heap[--sizeVar];
-    heap[sizeVar] = NULL;
+    heap[sizeVar] = nullptr;
     if (sizeVar > 0) downHeap(0);
     popped->heapIdx=-1;
     return popped;
@@ -68,7 +68,7 @@ void BinaryHeap::remove(Node *node)
 {
     // This is what node.heapIdx is for.
     heap[node->heapIdx] = heap[--sizeVar];
-    heap[sizeVar] = NULL;
+    heap[sizeVar] = nullptr;
     if (sizeVar > node->heapIdx)
     {
         if (heap[node->heapIdx]->f < node->f)
@@ -145,7 +145,7 @@ void BinaryHeap::downHeap(int idx)
         if (rightIdx >= sizeVar)
         {
             // Only need to compare with left.
-            rightNode = NULL;
+            rightNode = nullptr;
             rightCost = Float::POSITIVE_INFINITY;
         }
         else