Formatting: adhere to style guidelines

Added spaces between control statements and test cases
Docs: change redundant comment for clarity
Fixed: viewerWidthPadding margins still present when enableAutoWidth is off

According to the code documentation for viewerWidthPadding, the margin should not be present unless enableAutoWidth is on. This makes sense, as when someone is embedding Diva into a webpage, they would probably prefer to control Diva via CSS, just as they are controlling the presentation of all the other elements on the page.

Refs #147
Fixed: when enableAutoWidth off, Diva does not proportionally resize

Now, when enableAutoWidth is off, Diva's width fills its parent element. For example, if #diva-wrapper has a width of 700px, Diva does not add margins and does not exceed this width, which is much more reasonable behavior for integration with existing webpages.

Fixes #147