Version update for Transcrypt: 3.9.2

[JennaSys]

v3.9.2

Changelog:

• Add start argument to enumerate function
• Added missing bin, oct, and hex functions to built-ins
• Fixed the maxreplace argument of the string replace function
• Added start and end arguments to String startswith and endswith methods
• Added time.monotonic()
• Fixed typos in docs
• Cleaned up some repo cruft