Add "none" option to pager position configuration

If a savvy themer wants fine-grained control over the placements of the pager (i.e., if she wants to call theme('custom_pager', ...) herself at the theme layer), she must (1) use hook_nodeapi to remove the custom pager added in the "below," "above," and "both" positions or (2) choose the "block" position and ignore the block created by the module.

However! If a "none" option existed, the crazy-awesome theme could use her magic powers to insert the pager where she pleased without adding hook_nodeapi cruft or creating unused blocks.

What say you, Mr. Eaton? This may satisfy issues like this one: #694442: How to print link to next/prev link in node template?.