Load our custom banner-slide template rather than the default

This may be temporary, as the merge to Make 1.4.3 will allow us
to override the slideshow interface pretty easily.
Fork the banner-slide template from the original Make theme
Capture a slide URL if given
Wrap content with an anchor element in slides if it exists
Remove top and bottom padding from slide content

When padding causes the content to overflow the slide area and an
anchor exists, it will overlap the navigation circles and make it
impossible to use those without clicking the URL
Remove debug asdf
Merge pull request #129 from washingtonstateuniversity/link-slideshow-images

[PR] Provide ability to wrap slideshow slides with URLs