Add tagging script

This file includes the JS script to tag images, and the HTML/CSS for user input/output. The input files must be in a JSON format as exported by Metadata Games.

The getOAuthFunctionUrl function can be extended in the future to add different API capabilities.
Add comments and clean-up code

Removed irrelevant comments and added new ones pertaining to licensing. Also, removed a few lines of nonfunctional code left behind after a previous edit.
Merge branch 'gsolbeck-master'