Many doctest options are undocumented

Imported from <a href="http://trac.sagemath.org/sage_trac/ticket/12281">trac #12281</a>.



Reported by: mjo

Component: documentation

CC: kcrisman

Report Upstream: N/A

Authors: David Roe

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

Work issues: 

Reviewers: Jeroen Demeyer

Merged in: sage-5.9.beta1

Attachments: <ol><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/12281/12281.patch">12281.patch: </a> by roed at 20130315T00:17:57</li></ol>