Fix animation on deletion of a backend

The animation was happening just on the delete icon.

Note that we need to update the JSON first, otherwise we have some
glitch when redisplaying the backends.
Fix select widgets not having the proper values after a redisplay

We already had code for this, but it was only running on page load.

Also, this fixes some entries being visible while they shouldn't
(because data-hideit/data-showit events have to run after this).
Trigger data-showit events on redisplay
Use data-showit instead of custom js code for NetApp
Fix initial value of boolean selects

We need to convert the boolean value to a string, as otherwise setting
to false doesn't work.
Restrict the use of data-initial-value for cinder backends elements

We don't want to touch other elements (like the SSL ones) when
redisplaying backends.
Merge pull request #204 from vuntz/js-fixes

Various fixes in the js for multi-backend