make absprec argument of p-adics lift_to_precision optional

Imported from <a href="http://trac.sagemath.org/sage_trac/ticket/14294">trac #14294</a>.



Reported by: roed

Component: padics

CC: 

Report Upstream: N/A

Authors: David Roe

Dependencies: 

Work issues: 

Reviewers: Julian Rueth

Merged in: sage-5.9.beta1

Attachments: <ol><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/14294/14294.patch">14294.patch: </a> by roed at 20130318T10:08:54</li></ol>