NSZ 4.2.0

• Resolved title-intaller compatibility with python-zstandard versions later than 0.15.2. NSZ files compressed with modern zstd versions are confirmed to work on the latest Tinfoil, DBI, AtmoXL and TinWoo. Some abandoned title-installer who havn't updated will still be broken. See #120 (zstandard versions newer than 0.15.2 break compatibility with all title installers except DBI) for more information.
• Fixed a mistake in the FileExistingChecks code caused by specifying the wrong target file extension when calling CreateTargetDict. This fixes #123 (XCZ Source File Deleted before decompressing on the same output folder as original)
• Fixed NSP and resulting NSZ will be deleted using --rm-source when solid compression fails. This fixes #124 (NSP and resulting NSZ will be deleted using --rm-source when solid compression fails)
• Added crc32 hash of master_key_0e. Thanks to @16BitWonder for adding it!
• Implemented option to enable zStandard long distance mode for even better compression as requested in #117 (Add support for the zStandard long distance mode)
• Followed the python-zstandard author's feedback regarding flushing to fix all flushing related imperfections
• Fixed "'Counter' object has no attribute 'write'" error when using --create. This fixes #118 (--create is broken)
• Implemented directory expansion support for --create and improved documentation. This closes #119 (The syntax for --create is stupid and the documentation bad)
• Clarified the plaintext rule of the NSZ file format block compression extension as discussed in #120