Clarification of commas a bit more.

* Don't add a space when adding a newline... this just makes things messy if an editor doesn't support `.editorconfig`
* Separate out Comma Separator from Comma Operator
* Remove the `var statements` from Comma Separator *(plus it's an operator btw)* because we don't currently allow that under [Variable Declarations](https://github.com/OpenUserJs/OpenUserJS.org/blob/master/STYLEGUIDE.md#variable-declarations) and can confuse contributors.

Applies to #19
Merge pull request #205 from Martii/Issue-19StyleGuide

Clarification of commas a bit more.