2.0.0

This is the first release in the v2.0 series. While it should be backwards compatible with the 1.0 series, it has some major internal changes - in particular, it is now a binary module, rather than being pure Python. This is needed to integrate with Apple's new os_log logging infrastructure.

New features:

• Output redirection now writes to Apple's unified logging system (os_log) instead of the deprecated NSLog API. Output written to stdout and stderr appears in Console.app and log stream as before, but is now tagged with the OS_LOG_TYPE_DEFAULT and OS_LOG_TYPE_ERROR levels respectively, so the two streams can be filtered separately.
• The encoding attribute on the writer is now "utf-8" (previously "utf-16-le" / "utf-16-be"), reflecting the underlying API.
• Null characters (\x00) are now replaced with Java's "Modified UTF-8" encoding (\xc0\x80), rather than being silently dropped.