_s: Document background color fallback.

A default background color is needed for any time there is no custom background color.
This happens to use the browser's default `#fff`, and is meant more as a reminder for theme authors.

See #515.
Minor spacing fix for main navigation

Just an itsy-bitsy space removal, no biggie, but needed :)
Merge pull request #517 from emiluzelac/patch-29

Minor spacing fix for main navigation props @emiluzelac
Revert the change to spacing in #517

Adds back in space for now. Props @lancewillett
Changed lone uppercase H to lower
Correcting some irregular capitalisation and coding standards issues
Undid my multiline function corrections
Merge pull request #524 from jacklenox/dev

Capitalisation and coding standards corrections - props @jacklenox
Remove default widgets from sidebar
is_active_sidebar() check

Check to ensure sidebar is active before displaying #secondary
Remove unnecessary semicolon
Merge pull request #529 from Automattic/Remove-Default-Widgets

Remove default widgets from sidebar.

Closes #528.
_s: Use braces in all conditionals.

Formatting updates for file comment, conditional braces, and indentation.
ok