Correct refresh to seconds, improvements

- Ensuring `refresh` value is * 60 so its converted to seconds to pass to visualization getData call
- Changing private variable name from `_isLoading` to `_initialLoad` for better clarity in flow of code
- Conditionally checking on existence of scroll body element and that the scroll plugin has been initialized before calling `play()` or `pause()`
Merge pull request #52 from stulees/chore/refresh-seconds

Correct refresh to seconds, improvements