Improving Bing maps content script to have app namespace and Google codestyle

[heychirag]

Hello @ceilican

I am preparing my proposal for GSoC 16, which I'll submit soon. For demonstration purposes I am submitting a PR related to issue #10

Since reviewing this issue in it's entirety, in a single PR would be unfair to you. I will be sending multiple PRs resolving a small chunk at a time.

This PR changes the following file(s):

1. Source/BingMapsCarbonFootprint.js

In this PR:

• Added app namespace so that we do not interfere with other JS variables on page.
• Follow Google's JS guide.
• Zero Errors by Google JS linter 'gjslint'.
• Minor refactoring of some methods.

Thanks
PS: Sorry about the noise on this PR, still getting used what GIT is all about. Will send out remaining changes in a different PR.

[ceilican]

Thanks!!