Revert "Project modernization (#630)"

This code was not tested and breaks in Release builds, reverting to restore
functionality of the nightly. All in-game menus do not work and generating
a world crashes.

This reverts commit a9be52c41a.

Minecraft.Client/JoinMultiplayerScreen.cpp

@@ -7,7 +7,7 @@
 
 JoinMultiplayerScreen::JoinMultiplayerScreen(Screen *lastScreen)
 {
-	ipEdit = nullptr;
+	ipEdit = NULL;
 	this->lastScreen = lastScreen;
 }
 
@@ -55,7 +55,7 @@ void JoinMultiplayerScreen::buttonClicked(Button *button)
         vector<wstring> parts = stringSplit(ip,L'L');
         if (ip[0]==L'[')
 		{
-            size_t pos = ip.find(L"]");
+            int pos = (int)ip.find(L"]");
             if (pos != wstring::npos)
 			{
                 wstring path = ip.substr(1, pos);