multiple continue support, ipython, and more

[iloveitaly]

Some high level improvements:

• Multiple breakpoint()s were not working for me, now they are
• Logging is more consistent and does not use stdout
• Port + address can be customized via env
• ipython is (optionally) supported

Details:

• fix regressions triggered by (c)ontinue calls during a session
• fix: multiple breakpoints()
• feat: add @iex decorator
• feat: detect ipython
• fix: pdb import
• feat: optionally pull port and address from env
• fix: log target bind port, refactored logging
• fix: don't throw exception when port cannot be bound
• fix: newline on all errors, don't attempt to set debugger if we can't bind