Convert some of URL details to Jinja2

Anytime we have a loop with >100 items, the Django template engine
begins to be the bottleneck. This one is relatively straightforward to
convert, and sets the stage for converting the mirror status page as
well.

Signed-off-by: Dan McGee <dan@archlinux.org>
Convert mirror status tables to Jinja2

Yay for way improved performance. Local testing showed render times
going from 265 ms to 135 ms.

Signed-off-by: Dan McGee <dan@archlinux.org>
Make delay a property, not a function

And re-indent the URL details log template now that we've broken it out.

Signed-off-by: Dan McGee <dan@archlinux.org>
Break out available URLs into Jinja2 template

Signed-off-by: Dan McGee <dan@archlinux.org>
Remove percentage filter from Django templates filters

Signed-off-by: Dan McGee <dan@archlinux.org>