Fix issue #44 Custom scale on line graph doesn't start at origin (alternate fix)

I know that @ulrichsg submitted a request to fix the same issue (issue #44) but in my testing his fix breaks the default calculated scale functionality.  I fixed the problem by fixing the off by one issue and re-using the label population function resulting in less code overall.

By the way, I used the google closure compiler service to minify the javascript (it seems like that was the same one used for the previous minified code).