Doctest debugger doesn't work on OS X

Imported from <a href="http://trac.sagemath.org/sage_trac/ticket/14289">trac #14289</a>.



Reported by: roed

Component: doctest

CC: 

Report Upstream: N/A

Authors: Jeroen Demeyer

Dependencies: <a href="http://trac.sagemath.org/sage_trac/ticket/12415">trac #12415</a>

Work issues: 

Reviewers: David Roe

Merged in: sage-5.9.beta1

Attachments: <ol><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/14289/14289_doctest_readline.patch">14289_doctest_readline.patch: </a> by jdemeyer at 20130318T07:34:42</li></ol>