Two improvements to the silence context manager: If an exception occurs in the body of the with statement, restore sys.stdout/err so that the exception is displayed properly.  Also add a dummy flush method to _DummyFile as there is some code in distutils that calls sys.stdout.flush
Initial version of the ah_bootstrap.py script (name tentative).  This works similarly to setuptool' ez_setup.py in how it tries several different routes to find the astropy_helpers module and get it on sys.path.  The default is to just import it from a submodule called astropy_helpers--this is the default that will be used when running the astropy repo, for example.  But there are many other options.  I've tested out all the major use cases, but once I add a test suite to astropy_helpers it will be nice to have tests for the boostrap script as well.