Add location option to allow rendering an L&L layout before the closing head or body tags

Requested by Ben in an internal discussion. L&LLoops & Logic Loops & Logic is a templating markup language created by Tangible to simplify querying WordPress data layouts could theoretically be used as a replacement for those single-purpose plugins that insert headers and footers. To do this, there would need to be an option in the “location” menu of an L&L layout that would allow selecting whether the template should be loaded before the closing head tag or before the closing body tag.