quick way to debug testbrowser in doctests

Writing doctests I am sometimes wondering what is going on under the hood. Keeping this function around in my test environment makes it a bit easier to find out. After rendering the output to the browser it will pause waiting for a keypress to continue the test.  Note, this code works only on OSX though it should be trivial to modify for any OS.

>>> def render_browser(browser):
...   open('/tmp/browser.html', 'w').write(browser.contents)
...   import os
...   os.system("open /tmp/browser.html")
...   _ = raw_input()