Bug 8181 [REVISED] Replace DynArch calendar widget with jQueryUI version

Bug 8181 [REVISED] Replace DynArch calendar widget with jQueryUI version

All instances of the old DynArch calendar have been replaced with
jQueryUI versions and the old library files have been removed.

calendar.inc has been modified to include jQueryUI localization
strings and global configuration options. Just add a "datepicker"
class to an input field to trigger a datepicker prompt.

If you would like two fields in one from to limit each other (one
is date from, one is date to), add these classes to each:
"datepickerfrom" and "datepickerto." This will prevent an invalid
entry, e.g. a date in the latter which falls before the former.

jQueryUI is now upgraded to the latest verision, 1.8.21.

Edit: Now with proper translatability, date formatting, first day
of the week handling, and RTL support.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Ian Walls <koha.sekjal@gmail.com>
QA Comment:  rebased on current master; minor merge conflicts with other patches pushed

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>