Updated main.js after running through jsbeautifier.org to standardise indentation, etc.
Added global 'use strict' to main.js and updated code to avoid errors
Added JSHint options to main.js and updated code to validate; got rid of a few redundant brackets
With 4 spaces for wrapped lines
More indentation fixes
Changed test for null return back to test for undefined
Reverted - test for null return, not undefined
Deleted fields code; indentation tweaks
Merge pull request #71 from GoogleChrome/jshint

jshint: js code validation and beautification