Add custom background function to theme

[karmatosed]

Add the custom background function to the default theme

functions.php: ADD:

// This theme allows users to set a custom background
add_custom_background();

default.css body{}: CHANGE *remove the background image:

body {
background: #eaeaea;

[DJPaul]

This was fixed in r3458; I forgot to make a note on the commit, sorry.

karmatosed - Rather than take out the background gradient image, I switched it from the shorthand property to the individual properties which are then overridden by the CSS that WordPress inserts into the page head.

[DJPaul]

sidebar-footer.php was lifted from Twenty Ten, so props to the WordPress team for that, and I'm sorry again for forgetting to note this on the commit ticket.

[djpaul]

(In [3496]) Refactor functions.php to use appropriate theme-loading actions.
Improved support for custom thumbnails; now supports global page header as well as a per-post/page header.
Key functions are now hookable.
Add full phpDoc.
Props to the WordPress team and Twenty Ten for some of the phpDoc.
Fixes #2749, #2754, #2751.