updating addClass function to allow multiple classes and to prevent duplicates in IE9
update tests for multiple classes and to detect duplicates
update dist files
Merge pull request #38 from simeydotme/patch-addclass-2

Patch addclass
create a utility method to return a unique collection
update .parent(), .parents() and .add() to use $.unique()
update dist files and test cases
oopsy, meant to be parentElement