Create a mechanism for the user to specify whether they want to write the test data back to the test file or not

[anujgandharv]

Some users have come back and said that they do not want to write the data back to the test file and they would like this feature to turn on or off as per their convenience.
Currently the only easy mechanism to do it is by extending the existing DataLoader implementations and override the writeData method to do nothing. Something like this : https://gist.github.com/anujgandharv/6988214

But there should be a cleaner mechanism to do it.

[anujgandharv]

This is now available as part of the DataLoader annotation as well as a System Property "easytest.writeData".