added xor function preferredName.
Removed extraneous text and code from original assignment. Refactored preferredName function to make it shorter. Added a commented out ternary version of preferredName.
Made a few key changes to ternary operator function that I had forgotten to add before last commit.
One last refactoring of my function (based on other's approaches - yep, I finally peeked).
Changed implicit to explicit equal operator.
Removed equal sign typo in return statement
Merge pull request #27 from warmbowski/master

added xor function preferredName