Cleanup SCO - OPAC self checkout

Cleanup SCO - OPAC self checkout

~ vestigial broken scripts and templates removed
~ meaningless dependencies removed
~ Focus handling issues resolved for cross-browsers
~ Timeout only invoked for non-first screen.  This keeps the refresh from
flooding the logs continuously for no purpose.
~ two halves of "validuser" conditional linked in TMPL
~ elsif's used for $op conditionals

The focus should now appear on the "Return to Account Summary" button during errors.
The user can scan anything (w/ carriage return) and get back to the first screen.
Also, special functionality is added for the magic barcode "__KOHA_NEW_CIRC__".
This effectively ends the patron session and logs them out so the next patron can begin.
The purpose is for patrons to avoid having to use a keyboard at all, if libraries
print and have this special barcode available for patrons at the SCO station.

Enhancement was requested by Plano Independent School District.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>