Test for GSoC 2014 completed 

Hi, this is my implementation of the S3 method for CrossTable. Utilized the `pandoc.table()` to print the final result and some small tricks were used to make the output more similar to your example. A `digits` parameter was implemented to control the digits of numbers. I'll send an email to you to apply  for the GSoC project later, just want you to see this as early as possible. Thanks!

Ric