incorporate suggestions from Patrick Rapin, savejson can save to a file
incorporate suggestions from Patrick Rapin, savejson can save to a file

git-svn-id: 0dfcd2cbfde11cd338b51061f2a1a040b934da89@368 786e58fb-9377-0410-9ff7-e4ac0ac0635c

fangq/jsonlab,fangq/jsonlab