Merge pull request #5 from trekkie4life/event

Edit event and manifest
edit manifest file
Merge pull request #6 from trekkie4life/manifest

edit manifest file
Add background.js, Add tab listeners
Add clean function to only change display for elements it finds

Incorporate Chrome API to communicate with background.js on
ActiveTabs
Add background.js - incorporate Chrome API tools for adding
listeners for active tabs
Remove icon because this should run when the tab becomes active or on first load