Bugfixes and some optimizations

Bug fixes, notably the autoText message is now parsed correctly into an actual message rather than just a number. More fine-grained error checking, so that the user knows more about what they did wrong and how to fix it. Finally, an optimization which is using .NET framework 4.5.1 and not placing blocks to the map if they already exist. This prevents needless requests to the server and fixes a rare issue if you try to place a block that you don't have but already exists on the map, it will stay on the map (and not to default to null).