Consider adding a DEBUG-level handler to get_ipython().log

[danielballan]

This produces some useful additional output at startup, logging each startup script that is run. It doesn't appear to add much non-useful noise, from a user point of view.

ip = get_ipython()
ip.log.addHandler(...)
ip.log.setLevel(...)  # maybe not needed?

[danielballan]

Closed by #80