added the ability to filter a list of locations for the `edd_locate_template()` to check. As an example, I can now check my plugin for my own checkout_cart.php file, which is awesome.
added numerical priorities based on indexes so user can "inject" a location before/after things very easily. also fixed a trailing slash problem for child/parent stylesheets
Merge pull request #1717 from carldanley/master

added the ability to filter a list of locations for the `edd_locate_temp...