clipboard: gracefully handle missing scrap module
updated comments header for backends
cleaned up unicodepage comments
unicodepage code cleanup
prepare for addding box-protection to utf8 converter
adjusted loading order of backends and redirect to ensure codepage has been loaded
Prepare for box-drawinf protection in redirect (2)
implement box-drawing protection for redirected utf8 output
unicodepage box-drawing code cleanup
config.py: cleanup & commenting; added global dict to prepare for better option use by modules
config.py (oops): cleanup & commenting; added global dict to prepare for better option use by modules
tokenise.py use new config dict
tokenise.py use new config dict (2)
debug.py use new config dict
statements.py: use new config dict
expressions module: use new config dict
sound module: use new option dict
on_event: use new config dict
prepare_keywords() --> prepare_logging()
pcbasic main.py: removed unused imports