Properly parse zero-length strings
Add vinbt tool

Add a tool that utilizes norbert to edit NBT files with a text
editor.
vinbt: Squash bug in temp file creation

Before this change, `vinbt path/to/file.dat` would cause vinbt to
fail.
Save changes if writing new NBT file fails
Merge branch 'vinbt' into devel
Add more nbt formats to gitignore