added 'builtin' to getsource to account for calls to getimport for builtins; better detection of bad repr in getimport -- catch '<>' in dicts, lists, etc; better resiliance in importable -- if getimport fails getsource and vice versa; reverted getimportable to point to importable
added 'builtin' to getsource to account for calls to getimport for builtins;
better detection of bad repr in getimport -- catch '<>' in dicts, lists, etc;
better resiliance in importable -- if getimport fails getsource and vice versa;
reverted getimportable to point to importable


git-svn-id: df3a7ed15ef7bc1bd4e913d3c8231ba6def0a9e6@646 8bfda07e-5b16-0410-ab1d-fd04ec2748df

mindw/dill,wxiang7/dill