Reformatted addclear.js to use boilerplate template

Dropped the existing plugin into the basic jQuery boilerplate found here:
https://github.com/jquery-boilerplate/jquery-patterns/blob/master/patterns/jquery.basic.plugin-boilerplate.js

This allows addclear.js to be used on multiple matching targets.
Merge pull request #11 from jameswragg/patch-1

Reformatted addclear.js to support multiple targets