Fixed HugeNbtFileTest taking up 2x as much memory as intended. Added NbtFileTests.RootTagTest to check a few rare interactions with NbtFile.RootTag
Ok just a few more unit tests for edge cases. We're at 95% coverage now, woo.
Replaced a few nearly-impossible-to-trigger null checks with Debug.Assert(). Added [DebuggerStepThrough] attribute to NbtBinaryWriter's Swap methods. Got tired of stepping through them. Streamlined code responsible for tag renaming slightly.