Turn inspections up to 11

OK, so let's get this out of the way, there's some actual changes mixed
in here too. I'm really sorry:
 - Turtles can now not be renamed with unnamed item tags (previously it
   would clear the name, this seemed a little unideal).
 - commands.getBlock(s)Data will also include NBT.

Now, onto the horror story which is these inspection changes:
 - Make a lot of methods static
 - Typo fixes
 - Make utility classes final + private constructor
 - Lots of reformatting (ifs -> ternary, invert control flow, etc...)
 - ???
 - Profit!

I'm so going to regret this - can pretty much guarantee this is going to
break something.

src/main/java/dan200/computercraft/shared/TurtleUpgrades.java

@@ -6,7 +6,6 @@
 
 package dan200.computercraft.shared;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
@@ -27,9 +26,11 @@ public final class TurtleUpgrades
     private static final Int2ObjectMap<ITurtleUpgrade> legacyUpgrades = new Int2ObjectOpenHashMap<>();
     private static final IdentityHashMap<ITurtleUpgrade, String> upgradeOwners = new IdentityHashMap<>();
 
+    private TurtleUpgrades() {}
+
     public static void register( @Nonnull ITurtleUpgrade upgrade )
     {
-        Preconditions.checkNotNull( upgrade, "upgrade cannot be null" );
+        Objects.requireNonNull( upgrade, "upgrade cannot be null" );
 
         int id = upgrade.getLegacyUpgradeID();
         if( id >= 0 && id < 64 )
@@ -44,7 +45,7 @@ public final class TurtleUpgrades
 
     static void registerInternal( ITurtleUpgrade upgrade )
     {
-        Preconditions.checkNotNull( upgrade, "upgrade cannot be null" );
+        Objects.requireNonNull( upgrade, "upgrade cannot be null" );
 
         // Check conditions
         int legacyId = upgrade.getLegacyUpgradeID();