Sidebar Options - Top and Bottom

[baerkins]

Build sidebar conditions that allow more 'clear' control of sidebar location and order:

• Add new definition: define('SIDEBAR_DEFAULT_LOCATION', 'top');
• Allow definition to determine if sidebar comes before (top) or after (bottom) main content by default.
• Create new conditional allowing order to be swapped, something like switch_sidebar_order()
• Change define('SIDEBAR_DEFAULT_LAYOUT', 'left'); to define('SIDEBAR_DEFAULT_SIDE', 'left');
• Change sidebar_switch() to switch_sidebar_side()
• While you're at it, get rid of the uppercase on all of the definitions.