ENH: pull pandasjson back into pandas
DOC: add ultrajson license
TST: json manip test script. and trigger travis
BLD: fix setup.py to work on current pandas
CLN: revised json support to use the to_json/read_json in pandas.io.json

DOC: docs in io.rst/whatsnew/release notes/api

TST: cleaned up cruft in test_series/test_frame
DOC: io.rst doc updates
API: to_json now writes to a file by default (if None is provided it will return a StringIO object)
     read_json will read from a string-like or filebuf or url (consistent with other parsers)
ENH: removed json argument, now path_or_buf can be a path,buffer,url,or JSON string

     added keywords parse_dates,keep_default_dates to allow for date parsing in columns
     of a Frame (default is False, not to parse dates)
ENH: added date_format parm to to_josn to allow epoch or iso formats (which both can be

     can be parsed with parse_dates=True in read_json)
BUG: patch in weird nested decoding issue, courtesy of @Komnomnomnom
Merge pull request #3804 from jreback/ujson

ENH: add ujson support in pandas.io.json