Update jscalendar to 1.0 and add missing languages

Source downloaded http://www.dynarch.com/projects/calendar/old/

The following files were modified from upstream, to fix errors when
minifying the js:

 - calendar-he-utf8.js: added missing " on string
 - calendar-hr.js: fixed file header (BOM)
 - calendar-sr.js: fixed file header (BOM)

Source was minified with UglifyJS (https://github.com/mishoo/UglifyJS)

Fixes #11489
MantisGraph: Implement localization of jscalendar date selector
WIP - testing jscalendar language files
WIP more lang fixes