update CHANGES for v3.1.3
Mark as 3.2.0-dev.
Initial stab at for_json hook for C extension.
Implement for_json kwarg; pure Python version; add tests; update documentation.
Version bump to 3.2.0 for the hell of it.
make argument order for c_make_encoder match make_iterencode
update CHANGES and tests
ignore_nan #63
update release date
pass-through in decoder for lone surrogates #62
Merge remote-tracking branch 'upstream/master'

Conflicts:
	simplejson/encoder.py