Rename MyCtrl1 to AdminCtrl
Split user-data template out into separate file

This took way longer than it should have to get working,
because there was an unfortunate interaction between
CodeIgniter and Angular. When I had the partial HTML
file as a file in the same directory as the rest of the app
code, the CodeIgniter controller (which manages anything
with /app in the URL) was taking over to try to render the
/app/admin/partials/userdata.html URL. But the controller
is set to load the header and footer and Javascript (and a
few other things as well), which in turn was causing the
Angular Javascript code to load, which in turn was causing
the userData directive to try to load its partial view. Which loaded /app/admin/partials/userdata.html, which the
CodeIgniter controller took over... and so on and so forth.

So I've moved the partials directory to the root of the src/
tree, which is also the root of htdocs and thus Apache's
DocumentRoot. And our Apache config is set up to check
first if the URL corresponds to a real file, and if so, not to
hand that URL over to CodeIgniter's index.php. So as long
as we tell Angular to load partials from /partials/foo.html
(as an absolute, not relative, URL), we should avoid this
nasty infinite-loop bug.