Hide the "color" label with JS and remove an unneeded <br />.
Make sure the plugins classes can't be extended for the first version.
Inline doc updates.
Make the 'wp-color-picker' script a dependency for our custom backgrounds script.
Better methods for validating and sanitizing the background post data.  Also, a couple of bugs cleaned up.
Earlier check for whether the post type supports 'custom-background' so that we're not loading JS unnecessarily.
Prefix the custom field keys with `_`.
readme.md overhaul.
Version bump to 0.1.0-beta-1.