I renamed some functions to conform to the PEP 8 (and have more readable function names). I prefer to do it today instead having to keep ugly names for years :-)

Functions are now:

 * enable(file=sys.stderr, all_threads=False)
 * disable()
 * is_enabled()

 * dump_backtrace(file=sys.stderr, all_threads=False)
 * dump_backtrace_later(delay, repeat=False, file=sys.stderr, all_threads=False)
 * cancel_dump_backtrace_later()

 * register(signum, file=sys.stderr, all_threads=False)
 * unregister(signum)

 * sigbus()
 * sigfpe()
 * sigill()
 * sigsegv()

Refer to the README file for the details.