Bug 12137: Extend CalendarFirstDayOfWeek to be any day

Bug 12137: Extend CalendarFirstDayOfWeek to be any day

Mubassir Ahsan asked on the Koha mailing list:
Is there any option to set Saturday as the first day of
the week? Please help me.

CalendarFirstDayOfWeek is currently either Sunday|Monday.

By converting it to 0|1|2|3|4|5|6
(Sunday, Monday, ..., Saturday), we can allow any day of the
week to be the first day of the week in the date picker.

TEST PLAN
---------
1) Backup DB
2) In mysql:
   > DELETE FROM systempreferences;
   > SOURCE .../installer/data/mysql/sysprefs.sql
   > SELECT variable,value FROM systempreferences;
   -- It should say 'CalendarFirstDayOfWeek' and '0'
      May say '1' if you are using Norwegian.
3) Restore your DB
4) .../installer/data/mysql/updatedatabase.pl
   -- If your previous value for 'CalendarFirstDayOfWeek' was
      'Sunday', it should be '0'. For 'Monday', it should be '1'.
5) Test an installation with 'de-DE' as the language.
   -- The default value should be '1'.
6) Test an installation with 'nb-NO' as the language.
   -- The default value should be '1'.
7) In the staff client, confirm that any day of the week is
   available in the I18N/L10N system preferences for the
   CalendarFirstDayOfWeek dropdown.
   -- I'm aware they aren't in order, but I'm after
      functionality, not finesse.
8) In another tab, go to a staff place that has a datepicker.
   For example, Home -> Tools -> Inventory/stocktaking
9) For each possible value in the CalendarFirstDayOfWeek,
   go to the other tab, refresh the page after updating the
   system preference, and click the datepicker icon.
   -- The date picker should then start on the selected
      day of the week.
10) Log into OPAC
    -- This may require setting: opacuserlogin to 'Allow'.
11) Click the personal details tab on the left.
12) There is a date picker for the date of birth.
    -- The date picker should then start on the selected
       day of the week.
13) Run koha QA test tools.

NOTE: not an atomic update, since this is an old patch.

Signed-off-by: Indranil Das Gupta (L2C2 Technologies) <indradg@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>