Add options 'pretty' and 'sortarrays' for modifying output.

Adding pretty:true to options will produce output more like util.inspect(), i.e. like
standard javascript.

Adding sortarrays:true will sort every array, which is sometimes useful when determinstic
results are required and array ordering is not significant.
Add documentation to readme.markdown for opts pretty & sortarrays.
Merge pull request #1 from jimlloyd/feature/pretty-and-or-sorted-output.2

Pretty and/or sorted output