Bug 8955 - Self checkout should degrade gracefully with JavaScript turned off

Bug 8955 - Self checkout should degrade gracefully with JavaScript turned off

Several changes in this patch, the largest of which is that the
renew/return dialogs no longer require JavaScript in order to properly
alter and submit the form. Instead each button uses a separate form.

To test, log in to self checkout and submit a barcode which is checked
out and can be renewd, and a barcode which is checked out but has
reached the checkout limit. On the resulting dialogs each button
should function properly.

Also changed: I removed some useless JavaScript processing related
to a bogus "valid_session" variable which was unused.

Similarly removed is template logic based on a "timedout" variable which
was not set by the script. Note that the script contains NO server-
side handling of timeout. Timeout is dependent on JavaScript.

To test these changes, confirm that with JavaScript enabled you are
automatically logged out after the time specified in the SelfCheckTimeout
preference.

Other minor changes: Terminology and capitalization corrections,
minor style tweaks.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>